I like Oz, but I think he is so likeable because he's a blank slate, written as a slacker, without too much personality. He's so laid back, from what I remember he only loses his temper twice in the show, and both times he was being protective of Willow. I actually find him quite bland when compared with other characters who had more depth.
Are you an Oz fan, and if so why . . . or why not?