I used to have a huge list of webcomics but since the death of Google Reader I haven't been reading them as they update, but rather scraping them each month and shoving them in a comic book archive to read on the train. Buttersafe (http://buttersafe.net), Scary Go Round/Bad Machinery (http://scarygorund.com), Sinfest (http://sinfest.net), and of course xkcd (http://xkcd.org) are the only ones I still read. I also read Gunnerkrigg Court (http://www.gunnerkrigg.com/) but I first read it in print so I'm not sure it counts.
I love cyanide and happiness (I just got their depressing comicbook)
No mention of Perry Bible Fellowship (http://pbfcomics.com/) or Dinosaur Comics (http://www.qwantz.com/index.php)? For shame.
Thanks for recommending Gunnerkrigg Court - I love it!
No love for Dilbert?Yes we love dilbert:Show Image(http://dilbert.com/dyn/str_strip/000000000/00000000/0000000/200000/10000/1000/300/211322/211322.strip.sunday.gif)
Show Image(http://folk.uio.no/hpv/linuxtoons/dilbert-unix.png)