Bugbash http://www.bugbash.net/
Ctrl Alt Del http://www.ctrlaltdel-online.com/comic.php
Cyanide and Happiness http://www.explosm.net/comics/
Dilbert http://www.dilbert.com/
Dinosaur Comics http://www.qwantz.com/
Dueling Analogs http://www.duelinganalogs.com/
Filibuster Cartoons http://filibustercartoons.com/
Foxtrot http://www.foxtrot.com
Frank and Ernest http://www.comics.com/comics/franknernest/
I Drew This http://www.idrewthis.org/
IdiotBox http://www.mattbors.com/newstrip.html
Jeff Parker http://www.comics.com/editoons/parker/
Jeff Stahler http://www.comics.com/editoons/stahler/
Joy of Tech http://www.geekculture.com/joyoftech
Mike Luckovich http://www.comics.com/editoons/luckovich/
Miscellanea http://www.wellingtongrey.net/miscellanea/
Penny Arcade http://www.penny-arcade.com/comic
Perry Bible Fellowship http://www.pbfcomics.com
PvP Online http://www.pvponline.com/
Russell's Teapot http://russellsteapot.com/comics/
Saturday Morning Breakfast Cereal http://www.smbc-comics.com/
The Flying McCoys http://www.ucomics.com/theflyingmccoys
Truck Bearing Kibble http://truckbearingkibble.com/comic/
User Friendly http://userfriendly.org/
VGCats http://www.vgcats.com/comics/
We The Robots http://www.wetherobots.com/
Working Daze http://www.comics.com/comics/workingdaze/
Wulffmorgentaller http://www.wulffmorgenthaler.com/
Xkcd