Umm, besieds drinking a tiny tiny bit, nothing really. Oh wait, stole a few cans of pop from a grcery store when I was 12...I was kinda pressured into it by a few older people though.
The most illegal thing I've ever done is drive my car with no proof of insurance, expired plates and an expired driver's license. If it makes any difference, I was on my way to renew my license when I got pulled over.
Did you tell the cop that? doubt he would believe it. Most illegal things i have done, smoke pot/tobacco (not 18 yet), drink underage, speeding but who cares about that.