It's hard for me to gain traction on a webcomic where the banners are so big you can't see even a tiny part of the comic without scrolling. (Yeah, I'm lazy. Sue Me.)
http://www.zapinspace.com/ -- Space opera, scruffy rebels vs. evil galactic empire
http://ansuz.sooke.bc.ca/bonobo-conspiracy/ -- probably will be enjoyed only by math/physics nerd and/or current or former graduate teaching assistants; but what do I know?