i have to agree with the things people have said, and i also think it's important that the author take the time to utilize the medium. show, don't tell. unless, of course, you have to. would you watch a movie where they just sat there and explained everything? no; that's boring. so why give us giant walls of text?
mostly, i just want to care about what's going on. i want to feel that the writer cares. it makes me start to care. the art and story/jokes have to do the rest lol.
seriously though, character development and art are probably the most important things. i can go without story for a while if the other points are strong enough.