We've all had experiances where we've had to share room with someone who quite possibly annoyed us or could have killed us in our sleep with no problem. Who, then was your "nightmare roomate"?
Mine was a nouveau-hippie (the kind that listens to Phish instead of the Dead). he was my first semester college roomie and he had late classes. so while I'd be getting up at 6:45 in the morning, he'd sleep til noon, suddenly remember he had to go to class, and stay up late watching TV. I haven't been able to go to sleep with the TV on since.