Well, first I would recommend reading some Hunter S. Thompson if that hasn't been done already. Beyond that I would say more Warren Ellis. Probably The Authority more than anything, though nothing he writes is bad, that's just probably the second most smartassed book he's done. It kinda went off into the wilderness after he handed it over to Mark Millar, but Garth Ennis came in and inserted his own character, Kev Hawkins, to play off the Authority with typically droll results. Kev had two miniseries and now has his own new title, A Man Called Kev.
I also really like the runs that both Ennis and Ellis did on Hellblazer. They've all been collected in trade paperbacks. For more freaky, snarky dystopia you can also try Grant Morrison's The Invisibles, direct ancestor of The Matrix, only also witty and written by a nutty Scot. It finished around 2000 and has all been collected. My favorite series of all is Preacher by Garth Ennis (art by Steve Dillon). I still wish I could find a "Fuck Communism" Zippo like Jesse Custer has.
Wry, rude sonsabitches who are nonetheless principled, smoke a lot and like to get into fights. That seems to be my thing. But of course Superman and Batman make me totally verrklempt, so I'm clearly not that 'ard.