Every morning, without fail:
Kevin and Kell (slightly sappy, but good clean fun)
Sluggy Freelance (worship the comic)
GPF (though the current Terminator-wanna-be storyline is souring on me)
PvP (even if Scott Kurtz seems to be a putz)
Sinfest (booty booty booty!)
Dork Tower (IT MUST BE MINE!)
Penny Arcade
The Joy of Tech
Sinfest, of course, and then matt_mcl* got me hooked on BmB
Shibby 
www.penny-arcade.com <— Freaking HILARIOUS. I love these sick bastards. The only one I actually check religiously for updates.
http://jackiesfridge.keenspace.com <— Anything with an evil guinea pig is fine by me.
www.boxjamsdoodle.com <— Sky-blue genius.
www.avalonhigh.com <— Pure Canuck goodness, artfully mixing humour with actual storylines.
www.choppingblock.org <— The sickest, funniest damn thing you will ever see. You’ll hate yourself every time you laugh, and it is so worth it.
www.crfh.net <— Again, humour and storylines artfully mixed.
www.faans.com <— I don’t have words. Genius, pure and simple. Read from the beginning or prepare to be TOTALLY confused.
www.goats.com <— Hysterically funny. Another one like Chopping Block.
www.lethaldoses.com <— Love Hot Soup. Love the comic.
http://machall.keenspace.com <— Now defunct, but read the archives. College life, ahhh…
www.reallifecomics.com <— More gamer humour. With big swords!
The Japanese Beetle! A Superhero Web Comic! <— Awesome parodies of the superhero genre.
www.sinfest.net <— Come on, I have to say anything about Tatsuya?
andygirl, I also diligently read thinhline, then when it become sexylosers read it too. Now it’s gone AGAIN, indefinitely. I just hope Clay/Hard brings it back. 
Sick, sick, funny shit.
Joyfulgirl, I had totally forgotten BmB! AAAH!
rjung, Scott Kurtz is a total jackass. That’s the whole reason I stopped reading his comic. :mad:
Dragonblink, you can’t mention 8-Bit Theatre without providing a link! Swordy swordy swordity swordy swordy swordity swordy swordy… swordchuks, yo!
Y’know, in retrospect, the word “sword” is a really odd word…
As well as Sluggy, Schlock Mercenary and The Japanese Beetle are my favourites.
As well as many others already mentioned, http://www.poisonedminds.com/ (fairly adult), http://www.megatokyo.com/ and http://www.aliendice.com/ (fluff but fun) are all good.
For just kinda wrong there’s The Parking Lot Is Full, not so good right now, but there’s some great stuff in the archives.
I, too, have to give props out to Sluggy.
My friend, Mike does a comic called Irritability for www.spaceagecomics.com which is really damn funny (although one of our friends recently stated it should be renamed “Inside Joke,” but that’s besides the point…)
Also, my current favorite is a new one known as Something Positive. One of my favorite aspects? The main character’s pink cat, who suffers from some strange bone disease and can be seen in various strips doing wacky things like melting through the air vents or being used as silly putty. I highly recommend this one. The last great story arc…a musical about Jesus entittled Nailed.
Afraid it has to be DILBERT but coming second in the race is Garfield.
I grew up with these guys.
;j
Well, I already posted this on the favorite comic strip thread, but I think it is worth repeating:
About a former porno actress who is dating a robot. Classic premise, exquisitely realized.
I am very glad that Boy Meets Boy has been mentioned.
Collrge Roomies From Hell http://www.crfh.net/ 
Also Acid Reflux as mentioned by several others. I wish this was a real religion. I might not mind joining. 
Supermegatopia is very cool but has the dreaded adult content , so I can’t post a link. But, hey–use your search engine.
Gotta second Penny Arcade. Love me some Tycho and Gabe. I even have a “Got Wang?” t-shirt.
I read most of the other ones posted here, but the only other one I read religiously is User Friendly. Usually has a good story and pretty funny.
http://www.soaprope.com <-- no gimmick, but just funny
http://www.goats.com <-- gimmick, and funny
http://www.ancientmessages.com/ <-- pretty cool,and she posts here
bunches of others already mentioned
Dr. Fun has kept me laughing for years. One of the first Internet comics. A good replacement for the F*r S**e.
“All your toast belong to us.” “The AV Police (To project and server).” Scenes from “Altered Steaks” and “Eggrunner”.
I have to second Something Positive for the same reasons. Elastic kitties need extra love!
The only other one I ever read with anything resembling regularity is Snail Dust. The main character, Ondine, has a magic snail that formed from the dust behind her computer. Since then it’s morphed into a butterfly, a clone of Ondine, and is now a daisy. It’s official title now is Snailyclonyflowerfly.
Jerkcity
Leisuretown
Everything else is lame cocksucking.
I have a fondness for Dex .
As am I, being one of the very earliest worshippers of Sandragoddess…
Shibby!
jayjay
Sluggy Freelance
User Friendly
Dilbert
8-Bit Theater
Without these, my day is incomplete.
Oh good. I was worried that I was going to be the first to mention CRFH.
Top 3:
CRFH It’s great fun. Stop by the forum as well. Just don’t let yourself be put off by how… enthusiastic… some of them are about the comic.
Schlock Mercenary Humour, good sci fi and interesting plots, despite a weak start to the comic. Together with CRFH my joint favourite comic.
Jack Slightly (in some places more than slightly) twisted comic. Sometimes I find it a bit too extreme. For the most part though it’s very deep and the author is good at making you care for the characters.
I read quite a few others, but those are the only ones I’d put on my favourites list.
(Incidentally, my first post to SDMB. Yay )
GPF
also like PVP and Bruno the Bandit, but GPF first
Ra Cha’ar - sexylosers is at keenspace now. http://sexylosers.keenspace.com