Let's see....worst place I've seriously taken girlfriends to.
-Parent's house (My mom is way too nice for her own good...comes off as scary, and my dad is a stone wall of emotion)
-Dorm room right after my roommate had apparently had a...wild night, I'll say, with his lady friend.
-An elevator that was stuck for two hours with just the two of us inside it.
-A friend's house where I had somewhat of a...fling with his sister a few nights while he was out of town.
And finally, the picnic from hell. I decided to take her out at midnight to an empty park and have a romantic, candle lit picnic in the grass. The blanket caught on fire, she stepped barefoot in dog crap, nearly got electrocuted in the park bathroom trying to clean up the dog crap, and finally, learned the hard way that the sprinklers turn on in the park around 2 A.M every Saturday night.
Most of those places ended in break ups...especially the elevator one, though one of those scenarios ended in a much, much happier outcome.