Phil recommends
Questionable Content - http://www.questionablecontent.net/
The 10 Doctors - http://comics.shipsinker.com/
Three Panel Soul - http://www.threepanelsoul.com/

Max recommends
Girl Genius Online - http://www.girlgeniusonline.com/
Looking For Group - http://lfgcomic.com/
Goblins - http://goblinscomic.com/

Kipfler recommends
XKCD - http://www.xkcd.com/
Saturday Morning Breakfast Cereal - http://www.smbc-comics.com/
User Friendly - http://www.userfriendly.org/

Fodd recommends.... well, he's busy right now doing science stuff probably

http://www.insignificantcomics.com because Max asked me to.