I Watch My Roommate Sleep Sometimes.
It's not creepy, or at least I hope it's not. :/ She looks so calm and peaceful when she sleep, and her soft breathing can sometimes lull me to sleep when I can't sleep otherwise. The soft, gentle, steady sound of her breathing remind me that everything's ok and relaxes my mind when I'm feeling really stressed out or depressed.
She's caught me watching her a couple times, and thinks it's weird, but she doesn't really mind it. It's not like I'm pulling up a chair and sitting there staring at her. It's just if I'm up late doing homework or something, and I happen to look over at her, I sometimes watch her for a little. It helps to clear my mind of all the stuff that's distracting me from my work.
Sometimes she snores tho, and that makes me laugh. :)