"We've been lucky," adds McCormack. "But more than that, it's heartening to know that we can appeal to so many people and still be true."

And the biggest truism that sets apart this otherwise classic four-character sitcom?
"All four characters wanna kiss men," says Jim Burrows, the veteran sitcom director who has helped guide the likes of Taxi, Cheers and now Will & Grace. While the four- some make that desire abundantly clear, Will & Grace doesn't "make an issue of sexuality," says Hayes. "It just shows these people for who they are." Gone are the days where topical sitcoms like Maude and All in the Family had "special episodes" with gay revelations (actually, they're not so long gone; a recent, almost quaint episode of Becker had the doc deal with his godson's coming out). Freed by the groundbreaking Ellen, Will & Grace has taken TV's portrayal of gay characters up a big notch by making their gayness secondary to funnyness.

Sure, Will will deal righteously with the occasional relationship with a closeted sportscaster (Patrick Dempsey's turn this past season), but the show perhaps makes more of a statement by not making a statement each week. "We're not writing to the left or the right," says Mutchnick, who points out the show has nabbed both GLAAD honors and People's Choice awards. "We're making a comedy that we want to appeal to as many people as possible."

But if there's never been a show before like Will & Grace, it's because there's never been a sitcom character like Jack. "To me, he's a totally different character, so hyperactive," says Burrows, who directed Andy Kaufman back on Taxi. When it comes to helming the Emmy-winning Hayes, he adds, "I'm just the editor."

Any good show with gays has to have an unflagging gay sensibility, which Jack -- and the whole series, in fact -- have in spades. With those tearjerker moments has come Audrey Hepburn-worthy style (starting with the sophisticated but playful ampersand that brings the characters together in the show's opening credits), pop culture references to the likes of Britney Spears, campy mincings, blatant bitchiness, Ab Fab-level partying, and diva appearances extraordinaire (Joan Collins and Cher).

Then there's that unheard-of- for-net-TV bawdiness. Though McCormack says, "Of course, we have boundaries that cable doesn't," Will & Grace is pushing the line and turning it around. These kids don't go for the chestnut Three's Company double-entrendre. Noooo. When a hormone-happy Karen read the naughty "homoerotic literature" that Jack pecked out earlier this year, she hubba-uttered things that could actually pass for blue fiction. "I'm surprised at how dirty the jokes are that get on," says Mullally, an Oprah Club book reader whose roots are in conservative Oklahoma City. Says Mutchnick: "From day one, we've been allowed to do what we want."

And in this sitcom of the new millennium, the fab four may even linger knowingly after tossing those double-entendres, much like performers in a vampy review. "It's totally intentional," says McCormack. "Just like the audience, we all grew up on comedies. Everyone knows where the badda-bum is, so we tend to comment on it." Like a surreal Magritte painting, "we're inside and out of the sitcom structure because even Will and Grace know it would be too easy to fall into cliches. We have to be smarter and surprise people."

Such on-your-toes energy has gained Will & Grace a reputation for being one of the most fast-flying, fun sets in television. Here, writers won't budge (there have been additions but no turnovers in the show's three years), and all four cast members are happy to banter and drop drawers. "A lot of those jokes, crazy faces and sounds are impromptu, not rehearsal," says Mullally. "It's like a party."

"We sing a lot on the set, hop on top of the piano," adds McCormack, who has nabbed lilting reviews for his starring turn as The Music Man on Broadway this year. Messing has doo- wopped "Love Will Keep Us Together" with McCormack on the show, the Chicago suburb-born Hayes hit the ivories at age five and started his career as a musical director, while Mullally has done How to Succeed in Business Without Really Trying on Broadway and has more recently put up a one-woman, avant-garde musical review. "All that harmony comes across on the show," says Burrows. "These people are happy with each other in real life."

There is one high note that the show has yet to hit: an all-out romance for Will, who is after all a good-hearted, good-looking, successful lawyer. While it may be a surprise -- and disappointment -- to some that the WB teen drama Dawson's Creek beat Will and Jack to the smack with a brief guy-guy kiss last May, McCormack for one is confident Will -- as critical and fastidious as he can be -- will fall in bed with the right guy. "He's a good catch, and someone will catch him eventually," says McCormack. Though NBC and the producers have been noncommittal, it's increasingly hard to doubt him, for the show's hit status even opposite CBS's new smash C.S.L is a sign the show will be around a while.

Kiss or not, Will & Grace has engendered a lot of love -- and inspiration. Since the series hit, Fox was emboldened to go gay with the John Goodman vehicle Normal, Ohio and CBS whipped up the he's straight/he's gay spin Some of My Best Friends. Though those shows fizzled, the nets aren't giving up as easily as they might've years ago; CBS is shepherding Say Uncle, a potential fall show with Ken Olin playing a gay man helping raise a nephew and niece.

Perhaps preemptively,Will's creators had a little shock for viewers -- and Jack -- in the season finale: it seems sitcomland's least-likely paternal character donated his unique genetic code to a sperm bank years back, and the son he never knew popped in to promise plenty of playful plots for next season. "It's a great way to ground the character," says Kohan.

By its mere nature -- and nurture -- Will & Grace continues to make TV history. Which is why its stars can't wait to get back to year four. Hayes understates that it will be "interesting" to see Jack play dad. Messing, who just wrapped a part as Woody Allen's girlfriend in the director's next movie, will push for more big schtick ("They have to pull me back sometimes," she giggles). Mullally, who just notched a turn as a trailer-park vixen in the upcoming satirical feature Uncle, toasts Karen as "a slightly fabulous survivor in the pantheon of gay icons" -- a character so embedded in gay culture that the West Hollywood video bar Revolver bookends Karen clips to Billy Joel's "Uptown Girl."

And while the in-tune McCormack is thrilled to say he is subletting on Broadway right now, Will is after his heart. "He's a terrific character," says the actor. "He has leading-man qualities that aren't hampered by macho tendencies."

Mutchnick and Kohan are eager to start up, too. "We went for it with this show, and now sometimes we find ourselves alone in our office laughing," says Kohan. "It's hard to believe we're the same losers that went to high school together."

Losers? Hardly. Kohan tells the story of a fourteen-year-old boy who wrote them that he had come out to his parents by showing them a tape of the episode in which Jack does the same to his mom. "After they watched the tape, the boy wrote that his parents looked at him with love and said, 'We get it.'"

JOHN GRIFFITHS is a Los Angeles freelance writer.