Alan Moore:

Alan Moore (born November 18, 1953 in Northampton) is a British writer most famous for his influential work in comics, including the acclaimed graphic novels Watchmen, V for Vendetta and From Hell. He has also written a novel, Voice of the Fire, and performs "workings" (one-off performance art/spoken word pieces) with The Moon and Serpent Grand Egyptian Theatre of Marvels, some of which have been released on CD.

Bibliography:

ABC Warriors
The Ballard of Halo Jones
The Bojeffries Saga
Captain Britain
D.R. and Quinch
Doctor Who
Future Shocks
Marvelman
Ro-Busters
Rogue Trooper
V for Vendetta
Swamp Thing
Watchmen
The League of Extraordinary Gentlemen
From Hell
Promethea
American Flagg!
Lost Girls
Voice of the Fire

This is by no means a complete list. If you want to know all of Alan's works, go to the Wikipedia entry or The Alan Moore fansite.

My personal favourites are his works for the comic 2000AD, especially "The Ballard of Halo Jones", and his graphic novel, "From Hell".