Phonogram -- Technically it's a comic about practitioners of music-based sympathetic magic, but really it's about britpop, and an excuse for the author to rant about music. There are extensive multi-page footnotes in every issue. A recent issue was composed almost entirely of Long Blondes lyrics. The first series was awesome, but the second one ("The Singles Club") is even better. I can't recommend this highly enough. I love a lot of the bands name-dropped in this comic, but even without the encyclopedic knowledge necessary to get all the gags, I can appreciate the absurd levels of ranty obsession that it takes to make something like this. Oh, and the art is incredible too.
Atomic Robo -- It's got kind of a Hellboy thing going on (Atomic Robo is a mechanical man built by Nikola Tesla who fights Nazis and Lovecraftian horrors) but it's a lot funnier. Love this.
Mister X -- MISTER X! Dean Motter! OMG! There was a new Mister X miniseries this year, and my heart went all a-flutter. If you don't already know this one, just go get the Mister X Archives, ok? It's Important.
Ignition City -- Fantastic retro-future premise about where old spacemen go to die. This is the best thing Ellis has written in years. Unfortunately, the ending is kind of weak, and the art is half great and half crap. Pagliarani draws incredible ray guns, space ships and intestines, but can't draw actual human faces to save his life.
Scott Pilgrim -- It's about slackers, mostly, and and ninjas, a little. At first I found the anime styling a little off-putting, but it's hilarious and zany.
The Boys -- A secret team devoted to beating the shit out of superheroes, just because they deserve it. Sometimes you need to see Superman get punched through the face.
Powers -- Still great, but it takes so long between issues I usually forget what's going on. I should probably switch to just getting the GN comps every 3 years or whatever...
Buffy Season 8 -- The first dozen or so were great, but it has been steadily losing my interest. I haven't given up yet because I'm a pathetic fanboy.
I still have not found a reasonable way to find out about new comics that I would enjoy that doesn't lose all the signal in the unrelenting noise of superheroes. (Oh look, another X-Men spinoff. The Nickelback of comics. Die in a fire.)
Also, some webcomics, of which my feed reader contains quite a few, in alphabetical order: