Well, the most annoying thing is the lack of homework everyone else does (It's 4 unit maths ffs. You're expected to be doing a lot of work). In itself that's not a problem, but it really angers me when they then complain about how they could've done better when we get exams back. There's also the issue of the amount of time we spend going over the concepts we covered the day or two before - again, not a problem in itself (and I thoroughly support teachers helping struggling students), but when the reason we have to go over it again is people not doing homework and just not applying themselves to the course in general, that's just not acceptable.
There's also the issue of most of the guys dry-humping up in the back of the classroom before class or during breaks, but hell,
it makes for good conversation between myself and the girl I sit next to .