John Wagner is the co-creator of Judge Dredd, Strontium Dog, Ace Trucking Co. and Button Man, amongst many othersm for 2000 AD. His graphic novel A History of Violence has been adapted into a critically acclaimed hit film by David Cronenberg.
Grant Morrison is one of the biggst writers in comics this century. Some of his titles are: Batman: Arkman Asylum, The Invisibles, JLA, We3, The New X-Men, All-Star Superman
Garth Ennis is another massive comics name, he is the author of, among others, Hellblazer, Preacher, The Punisher, The Boys.