The Unresolved Cliffhanger Hall of Shame

Double-Hangers
This is my term for actors and actresses who appeared in 2 unresolved cliffhanger shows. Here's the list of the few and not-so-proud (arranged by final airing of the 2nd show):

Paul Savior (Love of Life, Edge of Night)
Nancy Marchand (Love of Life, Edge of Night)
Mary K. Wells (Love of Life, Edge of Night)
Larry Weber (Love of Life, Edge of Night)
Keith Charles (Love of Life, Edge of Night)
Joanna Roos (Love of Life, Edge of Night)
Jane Hoffman (Love of Life, Edge of Night)
Margo McKenna (Love of Life, Edge of Night)
Ed Moore (Love of Life, Edge of Night)
Alan Feinstein (Love of Life, Edge of Night)
Robert Mandan (Soap, Edge of Night)
Maxine Stuart (Edge of Night, Hail to the Chief)
Robert Guillaume (Soap, Benson)
Caroline McWilliams (Soap, Benson)
Ron Harper (Love of Life, Capitol)
Jay O. Sanders (AfterMASH, Crime Story)
Judson Earney Scott (V, The Colbys)
Ed Marinaro (Edge of Night, Dynasty)
Kimberley Beck (Capitol, Dynasty)
Bill Campbell (Crime Story, Dynasty)
Barbara Stanwyck (The Colbys, Dynasty)
Charlton Heston (The Colbys, Dynasty)
Claire Yarlett (The Colbys, Dynasty)
Diahann Carroll (The Colbys, Dynasty)
John James (The Colbys, Dynasty)
Ken Howard (The Colbys, Dynasty)
Maxwell Caulfield (The Colbys, Dynasty)
Stephanie Beacham (The Colbys, Dynasty)
David Ackroyd (AfterMASH, Dallas)
Charles Grant (Edge of Night, Dallas)
William Prince (Edge of Night, Dallas)
Larry Hagman (Edge of Night, Dallas)
George Petrie (Edge of Night, Dallas)
Charles Grant (Edge of Night, Dallas)
Donald May (Edge of Night, Dallas)
Alice Hirson (Edge of Night, Dallas)
Marc Singer (V, Dallas)
J. Eddie Peck (Dynasty, Dallas)
Joel Fabiani (Dynasty, Dallas)
Peter White (The Colbys, Dallas)
Michael Parks (The Colbys, Twin Peaks)
Joshua Harris (Dallas, Twin Peaks)
Constance Towers (Capitol, 2000 Malibu Road)
Adrian Paul (The Colbys, Dark Shadows)
John Chappell (AfterMASH, New WKRP in Cincinnati)
Tawny Kitaen (Capitol, New WKRP in Cincinnati)
Michael Bell (Dallas, Sonic the Hedgehog) * Note: Bell's actually made quite a name for himself in animation, he even has 3 roles on Rugrats.
David McCallum (Sapphire and Steel, VR.5)
Linda Gray (Dallas, Models Inc.)
Leann Hunley (Dynasty, Models Inc.)
Frances Fisher (Edge of Night, Strange Luck)
John Vernon (Hail to the Chief, Duckman)
Dana Hill (Sonic the Hedgehog, Duckman)
Vincent Ventresca (Prey, Boston Common)
Teri Hatcher (Capitol, Lois & Clark)
Lane Davies (Good and Evil, Lois & Clark)
Kenneth Kimmins (Dallas, Lois & Clark)
Eddie Jones (I) (Dark Shadows, Lois & Clark)
Tracy Scoggins (Dynasty, Lois & Clark)
John Bedford Lloyd (Edge of Night, Remember WENN)
Candy Azzara (Soap, Caroline in the City)
Dana Delany (Love of Life, Superman)
Victor Brandt (Capitol, Superman)
Joanna Cassidy (Earth 2, Superman)
John Payne (Exo-Squad, Superman)
Billy Dee Williams (Dynasty, Code Name: Eternity)
John Neville (Silver Surfer, Peter Benchley's Amazon)
Carol Alt (Capitol, Peter Benchley's Amazon)
Pamela Gidley (Strange Luck, The Pretender)
Jaleel White (Sonic the Hedgehog, Grown-ups)
Cameron Daddo (Models Inc., F/X: The Series)
Carrie-Anne Moss (Models Inc., F/X: The Series)
Margaret Colin (Edge of Night, Now and Again)
David DeLuise (Edge of Night, Now and Again)
George Dzundza (Superman, Jesse)
Jim Fyfe (Dark Shadows, The Lone Gunmen)
Timothy Daly (Superman, The Fugitive)
Stephen Lang (Crime Story, The Fugitive)
Mykelti Williamson (New WKRP in Cincinnati, The Fugitive)
Chad Lowe (Now and Again, Popular)
Scott Bryce (2000 Malibu Road, Popular)
Lisa Darr (Profit, Popular)
Seth Green (Good and Evil, Tucker)
Traylor Howard (Boston Common, Two Guys and a Girl)
James Horan (Edge of Night, Roughnecks: Starship Troopers Chronicles)
Elizabeth Daily (Duckman, Roughnecks: Starship Troopers Chronicles) * Note: is also the voice of Rugrat Tommy Pickles
George Dzundza (Jesse, Roughnecks: Starship Troopers Chronicles)
Brian Drummond (Cybersix, Spiderman Unlimited)
Alexis Fields (The Secret World of Alex Mack, Moesha)
Gary Chalk (Exo-Squad, ReBoot)
Michael Benyaer (Exo-Squad, ReBoot)
Tony Jay (Lois & Clark , ReBoot)
John Mariano (Caroline in the City, Hey Arnold!)
Kath Soucie (Sonic the Hedgehog, Hey Arnold!)
Shari Belafonte (Sonic the Hedgehog, Hey Arnold!)
Jessica Alba (The Secret World of Alex Mack, Dark Angel)
Lawrence Pressman (Edge of Night, Dark Angel)
Hedy Burress (Boston Common, First Monday)
Joe Mantegna (Soap, First Monday)
Stephen Markle (Edge of Night, First Monday)
David Clennon (thirtysomething, The Agency)
Tiffani Thiessen (Two Guys and a Girl, Fastlane)
David Clennon (thirtysomething, The Agency)
Will Patton (VR.5, The Agency)
Michael J. Anderson (Twin Peaks, Carnivale)
Patrick Bauchau (The Pretender, Carnivale)
John Savage (Dark Angel, Carnivale)

Cliffhanger Magnets
Of course, some performers are unluckier than getting just two shows dropped with 'hangers. Here's a list. (This time, it's by alphabetical order of last name.)

Clancy Brown (Earth 2, Superman, Roughnecks: Starship Troopers Chronicles, Carnivale) * Note of personal interest: is also the voice of Eddie's dad on Lloyd in Space, and more famously, Mr. Krabs in SpongeBob SquarePants.
Joseph Campanella (Edge of Night, The Colbys, Dallas) * Note of personal interest: he's also the Master on Road Rovers.
Michael Dorn (Exo-Squad, Spiderman Unlimited, ReBoot) * Note of some interest: was also Worf in Star Trek DS9
Debrah Farentino (Capitol, Earth 2, Get Real)
Richard Newman (Exo-Squad, Spiderman Unlimited, ReBoot)
Ben Piazza (Love of Life, Dynasty, Dallas)
Emma Samms (Dynasty, The Colbys, Models Inc.)
Tracy Scoggins (Dynasty, Lois & Clark)
Michael T. Weiss (2000 Malibu Road, Dark Shadows, The Pretender)
Lane Smith (V, Good and Evil, Lois & Clark)
Ray Wise (Love of Life, The Colbys, Dallas, Twin Peaks)

Unresolved cliffhanger shows which have had at least four double-hangers (or cliffhanger magnets): Love of Life (14), Edge of Night (26), Soap (5), The Colbys (15), Dynasty (18), Dallas (19), Twin Peaks (4), Capitol (8), Dark Shadows (4), Exo-Squad (5), Sonic the Hedgehog (5), Models Inc. (5) Lois & Clark (7), Superman (6), Roughnecks: Starship Trooper Chronicles (5), ReBoot (5), Carnivale (4).
Most common "shares": Love of Life/Edge of Night and The Colbys/Dynasty (with 10 each).
Notes:
1. While researching data for the page, I happened to notice that Gidley and Wise also appear in the film "Landspeed" (about, as you might guess from the title, racing cars on the Bonneville Salt Flats). Don't ask how this is relevant to the page... I just happened to notice this.
An extra side note sent to me by "Aaron": Wise also reprised his Twin Peaks role in the film based on the series, which also featured Gidley as a girl killed a year before Laura Palmer.
2. Weiss was directly involved in 2 unresolved cliffhangers (in other words, his character was either put into danger, or providing the threat to another): he was raping Jennifer Beals in 2000 Mailbu Road's finale, and jumped off an exploding subway train in The Pretender's finale. In Dark Shadows, he was defending for Joanne Going in a witchcraft trial (but he wasn't involved in that show's hanger).
3. Also directly involved was Farentino: she was shot at the firing squad in Capitol, and was frozen in the Earth 2 finale. Plus, she guest starred in an ep of Duckman.
4. Samms' characters however, have "suffered" in 3 different series finales: She was abducted by aliens in The Colbys' finale, was kidnapped by a corrupt cop in the Dynasty finale and was shot by a hitman in the Models Inc. finale.
5. Double double involvement: Mykelti Williamson literally went down in the WKRP finale and the world distrusted Tim Daly's Superman. Both were shot in the finale of the Fugitive remake.
(All filmography data from the IMDB.)

The More, The Merrier? Not Really
Sometimes, the writers try to raise the stakes by leaving more than just one storyline in the balance, but these multi-hangers aren't less prone to cancellation than individual 'hangers. Check this out:

Soap (1981): Burt ambushed, Chester catches Danny and Annie in bed, Jessica in front of a firing squad.
Dynasty (1989): Alexis and ex-husband pushed off balcony, Blake shot, Krystle in a coma, Fallon and baby kidnapped.
2000 Malibu Road (1992): Roger beats up and rapes Perry, Jade discovers her dad has been trying to kill her, Hal shot, Joy struck by lightning.
Models Inc. (1995): Carrie sold into slavery in Central America, Grayson shot by hitman.
Boston Common (1997): Leonard tries to propose to Cookie, Tasha's job on the line, Joy hired as professor in Jack's department, Wyleen tells Boyd to move out.
Remember WENN (1998): Victor and Scott ask Betty about who to send overseas, Hillary reveals she's married to someone else, Eugenia proposes to Foley.
Peter Benchley's Amazon (2000): Karen and Jimmy in plane that's just flown into storm, Alex shows up at tribal execution with a Bible and a gun (the title of the ep, actually).
Moesha (2001): Jerome finds a postive pregnancy test in Moesha's apartment, Myles kidnapped (leading to Moesha fainting upon finding out).
The Lost World (2002): A bunch of characters get into trouble with historical figures, while Veronica looks at her mother's pendant.
Wolf Lake (2003): Kanin almost done figuring out about the clans, Sophia starting to change, viewers closer to finding out who shot Willard.
Fastlane (2003): Billie gets high, Deaq and Van taken over by Jay Mohr.
The Agency (2003): Terri and Stiles with exploding collar, Joshua with North Koreans.
Farscape (2003): Aeryn and John crystallized, Chiana blind.

The Long and Short of It
The longest running shows to end on a cliffhanger: The longest running show to end on a cliffhanger was also the first: Love of Life went 29 seasons (1951-80). 2nd is another CBS daytime soap, Edge of Night, with 28 seasons (1956-84), and in 3nd is yet another CBS soap, Dallas, which ran for 14 years (1977-91). Among non soaps, we have Benson which ran 7 years (1979-86). Among non CBS shows, there's ABC's Dynasty, with 8 years (1981-89).
The shortest running shows to end on a cliffhanger: While many shows are cancelled after just one season on a cliffhanger (the first being "V"), those shows are still lucky compared to these shows: 2000 Malibu Road ran just 6 eps (over a span of 17 days in 1992), and Hail to the Chief (1985) and Good and Evil (1991), both by Susan Harris of Soap, as well as Clone High (2003), ran just 7. Running a close fifth are Wolf Lake and Profit with 9.
Classifying them by the length of their run, here's what we have (in loosely chronological order).
More than 10 seasons (3): Love of Life (29, 1951-80), Edge of Night (28, 1956-84), Dallas (14, 1977-91)
5-10 seasons (7): Capitol (5, 1982-87), Benson (7, 1979-86), Dynasty (8, 1981-89), NewsRadio (5, 1995-99), Sliders (5, 1995-2000), Moesha (5, 1996-2001), Hey Arnold! (5, 1996-2002), Angel (5, 1999-2004)
2-4 seasons (37): Soap (4, 1977-81), Blake's 7 (4, 1977-81), Mork and Mindy (4, 1978-82), Sapphire and Steel (4, 1979-82), AfterMASH (2, 1983-84), The Colbys (2, 1985-87), Crime Story (2, 1986-88), Alf (4, 1986-90), Twin Peaks (2, 1990-91), thirtysomething (4, 1987-91), New WKRP in Cincinnati (2, 1991-93), Between the Lines (3, 1992-94), Exo-Squad (2, 1993-94), Sonic the Hedgehog (2, 1993-94), Christy (2, 1994-95), The Governor (2, 1995-96), Cardiac Arrest (3, 1994-96), Space Cases (2, 1996-97), Duckman (4, 1994-97), Boston Common (2, 1996-97), Lois & Clark (4, 1993-97), Remember WENN (4, 1996-98), The Secret World of Alex Mack (4, 1994-98), Cybill (4, 1995-98), Caroline in the City (4, 1995-99), Bugs (4, 1995-99), The Sentinel (3, 1996-99), Profiler (4, 1996-2000), The Pretender (4, 1996-2000), Superman (4, 1996-2000), Jesse (2, 1998-2000) Popular (2, 1999-2001), Two Guys and a Girl (4, 1997-2001), ReBoot (4, 1997-2001), Dark Angel (2, 2000-02), The Agency (2, 2001-03), Farscape (4, 1999-2003), Carnivale (2, 2003-05)
1 season or less (37): V (1984-85), Hail to the Chief (7 eps, 1985), Alien Nation (1989-90), Good and Evil (7 eps, 1991), 2000 Malibu Road (6 eps, 1992), Dark Shadows (1991-92), Dead at 21 (1994), Prey (1995), Models Inc. (1994-95), VR.5 (1995), Earth 2 (1994-95), Space: Above and Beyond (1995-96), Nowhere Man (1995-96), Strange Luck (1995-96), Partners (1995-96), Profit (9 eps, 1996), The Silver Surfer (1998-99), Mortal Kombat: Conquest (1998-99), Two of a Kind (1998-99), Cybersix (2000), Code Name: Eternity (2000), Grown-Ups (1999-2000), Now And Again (1999-2000), Roughnecks: Starship Troopers Chronicles (1999-2000), Get Real (1999-2000), Peter Benchley's Amazon (1999-2000), The Lone Gunmen (2001), The Fugitive (2000-01), Spiderman Unlimited (1999-2001), Tucker (2000-01), Wolf Lake (9 eps, 2001-02), First Monday (2002), John Doe (2002-03), Fastlane (2002-03), Free For All (7 eps, 2003), Clone High (2002-03)

Unresolved Cliffhangers -- Classified
By Genre:
Comedy: 20 (Soap, Mork and Mindy, AfterMASH, Hail to the Chief, Benson, Good and Evil, Alf, New WKRP in Cincinnati, Boston Common, Partners, Remember WENN, Cybill, Caroline in the City, NewsRadio, Two of a Kind, Grown-Ups, Jesse, Tucker, Two Guys and a Girl, Moesha)
Sci-Fi: 17 (Blake's 7, Sapphire and Steel, V, Alien Nation, Dead at 21, Prey, VR.5, Earth 2, Space: Above and Beyond, Space Cases, The Secret World of Alex Mack, The Sentinel, Sliders, Code Name: Eternity, Dark Angel, Farscape)
Soaps: 10 (Love of Life, Edge of Night, Capitol, The Colbys, Dynasty, Dallas, Twin Peaks, 2000 Malibu Road, Dark Shadows, Models Inc.)
Other Drama: 29 (Crime Story, thirtysomething, Between the Lines, Christy, Nowhere Man, Strange Luck, The Governor, Cardiac Arrest, Profit, Lois & Clark, Mortal Kombat: Conquest, Bugs, Profiler, The Pretender, Now and Again, Get Real, Peter Benchley's Amazon, The Lone Gunmen, The Fugitive, Popular, The Lost World, Wolf Lake, John Doe, Fastlane, First Monday, The Agency, Angel, Carnivale)
Animated: 12 (Exo-Squad, Sonic the Hedgehog, Duckman, The Silver Surfer, Cybersix, Superman, Roughnecks: Starship Troopers Chronicles, Spiderman Unlimited, ReBoot, Hey Arnold!, Free For All, Clone High)
By Network:
ABC: 14 (Soap, Mork and Mindy, Hail to the Chief, Benson, Good and Evil, The Colbys, Dynasty, Twin Peaks, thirtysomething, Sonic the Hedgehog, Prey, Lois & Clark, Two of a Kind, Two Guys and a Girl)
NBC: 13 (V, Crime Story, Alf, Alien Nation, Dark Shadows, Boston Common, Earth 2, Caroline in the City, NewsRadio, Profiler, The Pretender, Jesse, Tucker)
CBS: 12 (Love of Life, AfterMASH, Edge of Night, Capitol, Dallas, 2000 Malibu Road, Christy, Cybill, Now and Again, The Fugitive, First Monday, The Agency)
Fox: 14 (Models Inc., VR.5, Space: Above and Beyond, Strange Luck, Partners, Profit, The Silver Surfer, Cybersix, Get Real, The Lone Gunmen, Spiderman Unlimited, Dark Angel, John Doe, Fastlane)
Syndicated: 8 (New WKRP in Cincinnati, Exo-Squad, F/X: The Series, Mortal Kombat: Conquest, Code Name: Eternity, Peter Benchley's Amazon, Roughnecks: Starship Troopers Chronicles, The Lost World)
Other Broadcast TV: 14 [Blake's 7 (BBC), Sapphire and Steel (ITV), Between the Lines (BBC), Nowhere Man (UPN), The Governor (ITV), Cardiac Arrest (BBC), Bugs (BBC), The Sentinel (UPN), Superman (WB), Popular (WB), Grown-Ups (UPN), Moesha (UPN), Wolf Lake (UPN, originally CBS), Angel (WB)]
Cable: 12 [Dead at 21 (MTV), Space Cases (Nick), Duckman (USA), Remember WENN (AMC), The Secret World of Alex Mack (Nick), Sliders (Sci-fi, originally Fox), ReBoot (Cartoon Network, originally ABC), Hey Arnold! (Nick), Farscape (Sci-fi), Free For All (Showtime), Clone High (MTV), Carnivale (HBO)]