Here are a few rather odd and specific pet peeves:
1) Large groups of deaf people (yes, I am a horrible person).
This is because, like any other group of friends, they like to chat while they walk, and this raises a few problems. First off, like an ideal gas, their groups tend to expand to fill the volume of the hallway or walkway on which they are traveling (since the further they are apart from each other, the easier it is to make out what others are signing). Even a group of 3 can fill a fairly large hallway to the point that there's space between them, but not quite enough to dive through. Secondly, while signing they are watching their friends, rather than where they are going, so they are more likely to run into you, or run you off the walkway, or into a wall. Third, like any group of friends they tend to slow to a pace that makes snails look fast, all but oblivious to the screams of those growing ever more late because of them. Finally they are LOUD. You wouldn't expect it, but because they cannot tell how much noise they are making they tend to be rather loud, and the sounds they make are often rather obnoxious.
2) "Rowdy" college students.
There are too many specific things to name here, but some people need to grow up and start acting in a manner that is at the very least not criminal, or, dare I hope, not a complete embarrassment to the human race (and if they won't grow up, how about culling the **** population?).
3) Young children at play.
There is a day care center located across the quad from my dorm room. The noise those children make could drown out construction equipment. They seem to be engaged in a never-ending contest to out-scream each other (I kid you not, that's really what it sounds like they're doing), all while playing on playground equipment that could seriously use some WD-40. The overall effect is an endless cacophony of piercing shrieks. I would close the window, but the temperature my dorm room has a tendency to skyrocket if the window is closed.