Other than "Just About Everything", things that really piss me off are
-People who don't use turn signals
-People who make a complete stop before making a right turn
-Misuse of Apostrophes. Just because a word ends with an 's' doesn't mean it needs an apostrophe, dummy.
-Text messaging writing, like l8er and idk. Also, bars that use "Nite" as opposed to Night. Is the one extra letter really that hard to add?