I'm a bit of a bad student to live with, I'll admit that. My cleanliness isn't the best, but when someone is sick on the stairs and refuses to accept responsibility or clean it now that really grinds my gears.
I also hate people who rely on 'daddy' to finance their way through university despite wasting their money on top brand food and clothes. You waste the loan given to you by the government on absolute crap, and resort to your parents for paying accommodation. Learn to budget properly or you'll never make it in the real word.
Another thing, when students try something new to 'broaden their horizon' that really pisses me off. Eating Greek food won't change you as a person, now please shut up about it. And no, I don't want to hear about how you paid to volunteer in Uganda for two weeks, and made the world of difference.
People who get a 1st in their exams but don't have any common sense and don't know how to fry mince. Or cook pasta. Or clean a plate. Toast and cereal is as far their culinary expertise goes.
I could go on all day really, I don't really like your stereotypical student. In fact I hate them.