You know, a lot of people push Order of the Stick on me, having played D&D games and such, and while it got a few chuckles out of me, I never got much past the first 20 or 30 comics before losing interest. I felt that he would often use endless panels not as a way to continue to tell a story like a great comic would do, but instead to meander around the comic and add a bunch of filler before he got to the punchline. It was OK, but I couldn't get more out of it. I'm tempted to read more in case it gets a little tighter later, but I always felt it was a little weak.
The other one, though, I've never read, and considering I am a huge fan of Achewood which uses similar offbeat, non-final punchlines and awkward pauses to great effect, not to mention constructing a deep, outrageous universe that is so convincing you forget all the characters are animals, stuffed or otherwise. That is my number 1 online comic.