Pissing on the side of the highway >_>
I mean, when you GOTTA go, you just gotta.
Actual most ignored laws? (that's common, not some obscure thing like "no sex after 10")
Well I think going past stop signs, perhaps speeding when going past a yellow, burning rented media, porn? (I sure hope it's not really illegal....), piracy, not wearing a seatbelt, txting while driving, theft in school- that's not counting pencils and erasers :P...
Wow, there sure are a lot.