Continuing on the "creator racks", we'll move on to Warren Ellis.
This one is kinda hard, actually, because it would be really easy to default to TRANSMETROPOLITAN. Which is great and awesome, no doubt, but it seems too easy.
One of Warren's greatest strengths as a comics storyteller is his love of telling a complete story in a single unit. You can see this on display in FELL or GLOBAL FREQUENCY (both which also could easily make the cut), which are collections of single-issue stories bound up as part of a larger narrative, but I think that for this pick, I'm going to edge myself over to PLANETARY v1: ALL OVER THE WORLD AND OTHER STORIES (which is, actually, a pointlessly long subtitle, isn't it?), which is as much about stories and storytellers as anything else.
It opens with a war between the Pulp Heroes and the Super Heroes, moves to Gojira and Monster island, ghost detectives in Hong Kong, and has the best rethinking of the Fantastic Four and Hulk that modern comics have done. All wondrously self-contained, yet each moving the overall story a bit forward.
You can sum the book up with this line from issue #1: "It's a strange world; let's keep it that way"
There's also lovely lovely art by John Cassaday.
If there's one single complaint I could make it's that there's STILL one more issue to go (and we're getting on 2 years now... my computer says the originally solicited shipdate of the last issue was freakin' 2006) -- Although the story proper is done, and the last one is just an "epilogue" -- which means the final collection of the series can't come out until that happens. Hope they get that done soon!
Anyway, great great stuff, and well worth being in your collection.