With every album that U2 has released, they have come up with a new sound. They have always managed to reinvent themselves, and keep their music interesting and enjoyable. Here's their North American Discography:

(Click on the album)

Boy (January 1981)

October (October 1981)

War (March 1983)

Under a Blood Red Sky (November 1983)

The Unforgettable Fire (October 1984)

Wide Awake In America (May 1985)

The Joshua Tree (March 1987)

Rattle and Hum (October 1988)

Achtung Baby (November 1991)

Zooropa (July 1993)

Original Sountracks 1 (November 1995)-The Passengers: Brian Eno and U2

Pop (March 1997)

U2 The Best of 1980-1990 & The B-Sides