Because they're awesome.
Dr. McNinja
A comic about a Ninja who is a doctor, whose last name happens to be McNinja. He fights Giant Lumberjacks, Dracula on the Moon, Fake Ninjas, Zombies, Zombie Ninjas, and the current story arc has him fighting the great King Radical with a Unicorn from another dimension that was transformed into a motorcycle. It's awesome.
8-Bit Theater
Probably the longest running sprite comic on the internet, and it's still going. Pretty much a twisted, fucked up interpretation of the original Final Fantasy with more stabbing.
Rumblo
A host site for KC Green's shit, which is all good. The recently ended Horribleville, which was basically a comic about writing comics, and Gun Show, which is basically whatever random-ass ideas he comes up with, are my personal favorites.
Menage a 3 Occasionally NSFW
Gary, a cartoonist, is forced to find new roommates to help pay the rent after his previous two roommates came out of the closet and moved into their own place. Zii, a punk-rocker chick, and Didi, a tall, buxom amazoness, move in with him and wacky hijinks ensue. About 5-10% of the pages have boobs.
Awkward Zombie
Katie draws Smash Bros and WoW comics. And occasionally other video games. They am funny. That's about it.
Girly
The heartwarming tale of a girl named Winter and her, at first, not-so-willing Sidekick. They go on lots of Adventures together. Lots.
LegoRobot
MS Paint at its finest.
Eerie Cuties
Drawn by the same guy as Menage a 3, but this one has color and is about a school for Vampires and Werewolves and Succubi and that sort of shit.
Stuff of Legends
A Pokemon comic. The previous League Champion never defended her title and instead decided to fade into obscurity and lead a quieter life. That doesn't last too long though.
F@NB0Y$
One Nintendo fan, one Sony fan, and one Xbox Fan sharing a house together. Hijinks ensue.
Marry Me
A Pop star sees a random guy, named Guy, holding a sign during one of her concerts that says "MARRY ME!" on it and decides to go for it. Unknown to her, that sign didn't belong to Guy and guess what happens: WACKY HIJINKS!
In Wily's Defense Lots of talking
My personal favorite Sprite Comic, and the only other one on this list besides 8-Bit Theater. I'm sure I've plugged this one enough for you people to know what it's about, but just in case: It's essentially an alternate universe where Wily is the good guy and Dr. Light and Mega Man are evil. It gets deeper than that as the story progresses, but that's the basic gist of it. This comic is also one of the main reasons I'm such a huge fan of Pharaoh Man.
Fetch Quest
Written by the guy behind In Wily's Defense, it's sort of still getting started, but it's shaping up to be a pretty cool fantasy story.
NOW POST YOUR WEBCOMICS.
And no super popular shit like VG Cats or Bob and George that everyone knows about anyway.