"Flintlocke vs. the Horde" ended back in July, I believe. Still hilarious, though, as is the original "Flintlocke's Guide to Azeroth."
I read several that Polderan already mentioned (CAD, Gunnerkrigg Court, Girl Genius, LFG). All excellent comics.
I'd also add
Dominic Deegan,
Goblins,
Digger, and
Dead Winter to the list.
Dominic Deegan updates M-F consistently,
Goblins seems to update about once or twice a week,
Digger updates Tues and Thurs, and
Dead Winter's a bit sporadic but averages once a week. I'd also like to add my all-time favorite,
Zebra Girl, to the list, but I'm a bit hesitant as it doesn't update very regularly or consistently these days (maybe once or twice a month, if we're lucky). All of the web-comics I listed have excellent ongoing, consistent plots, and have spectacular artwork. Well, some of the early stuff can be pretty rough, but at least two of those comics are done by professional artists.
Fun Fact: Digger's drawn by the woman who created the original "LOL WUT?" pear, Ursula Vernon:
Link to original image on DA. The linked image is safe, but I'll put a NSFW warning on her gallery; she does some rather bizarre and risque paintings sometimes...
____________________________
"Fairy tales are more than true: not because
they tell us dragons exist, but because they tell us
that dragons can be beaten."
~ G.K. Chesterton
My jaw works madly.
From it, no sound emerges.
Dumb post kills all thought.
-Haiku for an Idiot Poster by Shador VIII (C)2009