Humor is a big driver for me. I am surprised that I don't find much interest in adventure comics. Instead, I prefer humor comics that are building up a story over time.
The style of art is also very important. Not the quality of art, but the style. I've never been interested in Manga, for example, so a clear Manga influence makes me glaze over.
Identifiable characters also help me a keep reading. By that, I mean I can tell that Joe isn't Bob. It's tough when someone makes all their characters look the same (unless that's somehow part of the joke).