I'm staying at St. Mark's. It's grotty, but nice and quiet. It's also incredibly close to the campus. I won't say it isn't ugly, but a lot of unis have halls that are a lot grottier. You have to balance convenience with luxury when you stay at Leeds.
The societies are good here. The nightlife is too. Shopping's better in Manchester, though. As for studying, there's plenty of libraries around - but it depends on what school you belong to.