My biggest fahsion pet peve by far is leggings. Most of the time I see them worn with ballet flats or heels which is all kinds of nasty. The 80's are over for a reason people! Also, the majority of girls I see in them are too big to be wearing them (and by big I mean weighing more than an infant, because you have to be tiny to pull this things off). But the worst by far is when people wear leggings as pants. I don't mean under a dress or long shirt, I mean as if they were a substitute for jeans. It drives me batty!
Sorry, rant over.