My roommate has done the following:

-not flushed the toilet on more than one occasion
-left used sanitary products on top of the toilet. Not in, but on top of.
-left a pan of food on the stove for a week until it grew mold
-left food in the fridge that has grown mold
-broken the garbage disposal three times. The first time resulted from her putting chicken bones in it. The last time she tried to fix it by pouring Clorox down the drain. Dirty water filled up the sink and sat there for a few days.
-never does the dishes. Ever. And I mean never. When it warmer out, there would be bugs on her dishes.
-leaves empty boxes of food on the table, on the floor, on the counter top.
-has heard squeaking coming from her room several times. I suggested she put out a rat trap but she said she'd probably step on it.
-bought a puppy which by the way is not potty trained. The dog crapped in my room the other day and also in the common area. When she cleaned up the poop she put it in our garbage can. And then never emptied the garbage.
-left her used gym socks on the kitchen table
-left her bloody underwear in the bathroom
-got period juice on the tub.
-when she went away for spring break she left her alarm clock on. It would go off at midnight, and since her door was locked, I couldn't get in there to turn it off so it would keep ringing for an hour until it shut itself off. I finally turned her breaker off. She had a mini fridge in her room with shrimp in it, and all the shrimp went bad and she had to clean it up when she got back from break. She doesn't know it was me.
-has let oatmeal and grits boil over and harden on the stovetop.
-left underwear on the couch in the living room
-has been making out with her boyfriend very loudly in the living room
-has had sex so loudly that my other roommate heard it from inside her own room. I was studying for a journalism test. She orgasmed multiple times.
-took baths until she started getting hives. She couldn't figure out why, until she took a Q-tip, swabbed the inside of the faucet, rubbed it on her skin, broke out in hives, then proceeded to tell me that we have mold in the faucet. Thanks.

I couldn't make this stuff up.