My favorite ever? Well, that would be Transmetropolitan by Warren Ellis, because I do loves the futuristic Hunter S. Thompson-esque Spider Jerusalem, easily one of the best characters ever... and, I mean come on, what's not to love about a comic where the characters are always popping on down to the local Black-ops Deli for some Chilean baby extract, or Caribou eyes? Or chainsmoking Carcinoma Angel cigarettes while plotting the downfall of a President also referred to as "The Beast" via renegade journalism and a bowel disruptor gun?

I've also loved Frank Miller's work, the Sin City series, and 300 which was a fave from WAAAAY the fuck before hollywood made it into a craptastic piece of feature-length propaganda... Miller's take on Batman was also really cool, I think it was called Dark Knight Returns? Something like that.

Current faves are Warren Ellis' Desolation Jones, and Fell, which he is collaborating on with Ben Templesmith, a super talented young artist from Down Under who also writes and illustrates another current addiction of mine, Wormwood: Gentleman Corpse. Totally great series btw, funny, creepy, and perverse in all the right ways... I think the title of the most recent story arc kind of sums it up: "Leprechaun Fight Night"... oh so fucking funny.

And the history nerd inside me is completely in love with Eric Shanower's epic attempt to turn the Illiad into a graphic novel with his Age of Bronze comic... a huge undertaking I must say, really, the depth that he goes into with his literary and historical research is amazing... and the drawing so well done and detailed as well... its no wonder he's on issue number 25 or so and the Greeks haven't even made it to Illium yet!

And as far as manga goes, my favorite ever is, of course, Battle Angel Alita... cyberpunk social commentary at its best!

Not for everyone, but i really like Loan Wolf and Cub.

Comics!? Did someone say comics!? Oh hell yes I love me some comics... ok favorite Trades? Ok. Preacher was excellent, you like Garth Ennis? Hmm, well I am huge on super heroes mostly but let me give you a list of some of my favorites:

Ok Hellblazer is definently up there, specifically the Garth Ennis, Brian Azurello, Warren Ellis, and Alan Moore runs. You can find a list here: http://www.hellblazertrades.com/

Ok I'll keep going I have nothing else to do:

Exterminators Volume 1,2, and 3 by Simon Oliver
The Walking Dead by Robert Kirkman
Invincible (Read the first 3 trades, if you're not hooked somethings wrong with you!)
Transmetropolitan

If you've never read the Watchmen, I would get that next, that book is so important to comic book readers its not funny. Alan Moore's finest work.

I'd also reccommend picking up the Ed Brubaker Captain America run, it's fantastic.

Brian K. Vaughn's first 3 volumes of Run Aways is spectacular.

The Mark Millar Spider-Man Marvel Knights has 4 volumes that are really quite good.

Try the Astonishing X-Men by Joss Whedon, that is a a great book too.

Also try Ultimates 1 and Ultimates 2 (each has 2 trades) the art is spectacular and the modern day avengers story is great.

Also I am a huge Warren Ellis fan, so here is some great stuff:
Next Wave: Agents of H.A.T.E. Volume 1 & 2
Desolation Jones
Planetary (He didn't do all of em, so start at the beginning)

Also I would highly reccommend you read The Authority, check amazon start at the beginning, and I dare you not to love it. I would recommend this next since you just finished Preacher and this book is so epic in nature. Just wait till you get to the trade where they fight God.

Hope this helps!

Have to say the best comic I've read is by far The Watchmen. It's a classic, and if you never read another graphic novel again this would be the one to end with.

I'm out of the comic book loop now but I was a huge fan of the X-men, Avengers, Batman, Punisher, and anything Frank Miller did.