My roommate ultimately made me decide to leave the dorms altogether after only a semester of living there.
Lighting became my biggest problem with my roommate. Turns out that she was afraid of the dark, and normally I wouldn't have had a problem with that if she wanted to have a nightlight or something, but she blew things way out of proportion. She had a nightlight set up in our dorm, but the thing was so bright I found it hard to sleep! When I asked my roommate if she could turn down the intensity just a tad, she basically said "no." Gee, thanks buddy! -_-
Then the lighting thing got worse around Christmas, when she bought Christmas lights to hang around the hallway and bathroom of our dorm, not to mention she bought smaller lights to hang around her desk. And all of these d*** lights were on 24 / 7! Enter the bunch of sleepless nights I encountered because of all the freaking lights! :p I can't tell you how many times I would wake up in the middle of the night to use the restroom, only to get bright light radiated into my pupils! What really sucked about this was the fact that my roommate was never really there to begin with; like she'd be gone 90% of the time. Would've been nice for her turn the lights off if she knew she'd be gone for the night, but nope. She had them on all day and all night! -_- I normally have trouble sleeping as is, but the lighting thing only made the problem worse!
The last straw for me, however, came in the form of a coffee cup. It was nothing special; it looked like something you'd buy from Starbucks, but I remember her leaving the thing on her desk, and it was still half full. She ended up leaving it on her desk for an entire month! You could see mold starting to grow in it, too, which was absolutely disgusting! So, not only did I have the light thing going on, but now I'd also be breathing in mold spores because my roommate was too lazy to throw the d*** thing away! :p Even when I asked her to throw the stupid thing out, she simply ignored me and left it there! I ended up having to be the one to throw it out, and it wasn't even my responsibility to begin with!
Now, I commute from home, and it's not even that bad. It's worth it just to get a good night's sleep alone. Turns out the person that ended up getting my room (after I left) also left the dorms, so I guess it wasn't just me having problems with my ex-roommate.