I think I should post my entire list of webcomics I read, even if they have finished for not. So, here goes... (Yeah, I'm going to duplicate some of the ones already said...)
Adventurers! by Mark Shallow
I know this is a comic everyone has to have read before, and if you haven't, go read the entire archive, NOW! The comic has ended, but it was a fun comic to read while it was still going on. I highly suggest reading it if you never have, again, NOW!
Antihero For Hire also by Mark Shallow
This comic takes place in the future and follows Shadehawk, a "super-hero" who works only at night. I like it a lot. It's by the same guy who did Adventurers!, so it must be good, right? >.>
Bob and George by Dave Anez
If you haven't read this one, you are missing out, unless you don't like Mega Man or sprite comics. This comic has to be one of the oldest, if not THE oldest, sprite comics in existance, but sadly, it's coming to an end because Dave has been doing it for 7 years now. He needs a break.
Comedity by Garth Graham
This is kinda a strange comic at first. The main character, Garth, apparently has several different aspects of his mind on some council in his head, his life seems to be anything but ordinary, and his computer is actually a hot chick named Alice. I dunno what else I can say about it. >.> Probably best to read it to make more sense of the nonsense.
Ctrl+Alt+Del by Tim Buckley
A very funny gaming-related comic, you have this crazy guy named Ethan who has a roommate named Lucas and their wacky lives. Ethan even built a robot out of an X-Box. How crazy, but it's a good comic, go read it.
DATAROM! by um... HazokiS (he didn't put his real name on the comic's page)
This is done by someone from BnG, most of you who read Kuro's comic Cuteness²+Evil³=Kirby! would've seen him as Cameo Man. It's about this guy named Ein who turns into a weredragon and the crazy hijinks that happen because of it.
Dominic Deegan by Michael Terracciano
A nicely drawn comic with an excellent storyline, this one is about a seer named Dominic Deegan (duh!) who uses his ability of Second Sight to help people, later on going on crazy adventures which almost get him killed. It's mostly fantasy-based, so there's a lot of magic in the world the comic takes place in. A good comic to read, though.
Dueling Analogs by Steve Napierski
This one I just started reading a few months ago, but it's another gaming comic which seems to focus mostly on making fun of gaming in general. I still recommend it, though.
Flipside by Brion Foulke
Quite an interesting comic, Flipside mainly focuses on this girl named Maytag who is usually always dressed up in a Jester's outfit, but has a very different personality when she's not wearing it. Still, the story is very well done, and I think you should read it.
Full Frontal Nerdity by Aaron Williams
Done by the author of Nodwick, this comic is about a group of table-top role-players. The funny thing is, it took the characters a couple months to actually learn each others names, even though in the comic's timeframe, they had been playing with each other for years before then. But it's a very humorous comic that I like to read, even if it only updates once a week.
General Protection Fault by Jeff Darlington
This comic started off focused around Nick Wellington, a computer programmer, who started work at a company called GPF Software. It later started to take plot twists here and there, and it turns out Nick has this thing called the Inventor's Gene, and he starts making things that really would not be possible in the real world. Sadly, the comic's update schedule has slowed to a crawl because of the author's real life, but all in all, it is still a good comic.
God Mode by Ryan Kerns
This comic is another gaming related comic, it focuses around the staff of an online game news site called God Mode Online, run by a very sadistic woman. But it's funny the way the rest of the cast is treated. A good comic.
MegaTokyo by Fred Gallagher
This is a comic based around two guys, Piro and Largo, who went to Japan but got stuck there when they maxed out their credit cards, and are trying as hard as they can to make enough money to go back home, which sadly hasn't been working out too well for them.
The updates are sometimes sporadic, but it still updates well.
N-Fans: The Comic by Lalala (formerly by Webster Swenson)
This comic started off as a small adventure for a group of fans of the old Captain N show going into Videoland, and later turned into a bunch of missions while in Videoland. Sadly, the original author of the comic passed away, and it just recently started again under someone else who is also in the comic. It's too early to tell if Lalala will do as well with the comic as Webster did, but let's hope she does. The archives are still a good read, though.
Nodwick by Aaron Williams
A comic about a henchman named Nodwick and the party he works for: a fighter named Yeager, a wizard named Artax, and a cleric named Piffany. Nodwick has a huge nose, carries EVERYTHING for the party, and because of Artax and Yeager, is usually killed in some way. Piffany revives Nodwick using Duct Tape. A very funny comic.
Online Life by SpoonyBard (he, too, did not put his real name on his comic)
A comic about a guy named SpoonyBard and all his friends who were part of the IRC channel he used to frequent. They regularly are fighting evil for some strange reason, but it's a funny comic. But Spoony sometimes has a terrible urge to do things OTHER than the comic...
Order of the Stick by Rich Burlew
A very hilarious Dungeon & Dragons 3.5e based comic, it focuses around this party called The Order of the Stick, who originally was on a quest to kill a lich named Xykon, but later were involved in a much larger plot. Go read it if you like D&D. ALSO on the site is a comic called Erfworld, by Rob Balder, which is kinda a silly stab at a world similar to those found in D&D. Not in the same realm of funny as OotS, but still funny.
Pebble Version by Josiah Lebowitz
A very funny parody of the Pokémon Ruby/Sapphire games, it takes you across Hoenn with May and Brenden, the two trainers you could choose to play as in the R/S games. It's very funny because it makes fun of so many ridiculous parts of the Pokémon series in general, and even some things specific to R/S.
Player vs Player by Scott Kurtz
Another semi-gaming comic, this shows what happens at a gaming magazine called Player vs Player, or PvP as it's also known as. The cast is very strange at times, and they even have a peaceful troll named Skull on their staff. A good comic, although I have noticed it sometimes doesn't update until mid-day instead of the morning like most other comics.
Real Life by Greg Dean
As yes, the first comic who's community I actually joined, forming the building blocks of my current online persona... Er... Back to the topic at hand, Real Life started off as nothing more than what goes on in Greg Dean's life, but eventually it become much more than that, and introduced a lot of elements that could never happen in real life. It's not as good as it used to be, but it's still decent, I think. Oh, and I have 2 text cameos during 2002. Look for them. >.>
Schlock Mercenary by Howard Taylor
A comic that takes place in the far future, it's about this Amorph named Schlock (an Amorph looks like a pile of crap, to be blunt), and the space mercenary company he works for. They get into a lot of fights and there's a lot of stuff that goes on in it. A very good comic overall.
Shortpacked by David Willis
Well, it's a comic about a toy store, run by a guy who thinks he is taking over the world for some reason. The cast is... well, crazy, to put it mildly. You just need to read it for it to make any sense, and even then, it doesn't.
Unshelved by Bill Barnes and Gene Ambaum
A comic about a library in a place called Mallville. The main character is a sarcasm male librarian named Dewey, who I think is one of the best characters in the world. >.> Read the comic, it's funny, damnit! Who knew a comic about a library could be funny, eh?
VGCats by Scott Ramsoomair
Yet another gaming comic, this one also makes fun of games, but the main characters are a male cat and female cat, both anthropomorphic. In any case, a lot of the game parodies are actually made to be very Not Safe For Work in some cases... but it's still funny.
Alright, most of the other comics on my list either don't update enough to mention (or have died prematurely), and I also have a collection of Bob & George fancomics that I read, but many of those are also dead in the water, with a few exceptions.