I live alone now, but I have before.
I had one roommate who was perpetually irresponsible. I don't mean that he didn't call his mother on Sunday. I mean he was always:
He was like 29 years old at the time. He was just a total prick.
Well, that's not totally fair. You don't blame a rabid dog for biting you or a coyote for howling at the moon. He was and is a child stuck in a man's body. What do you expect to hapen, right?
I was naive at the time. I thought that maybe he needed some slack and then he would get back on his feet. I gave him the benefit of the doubt. Turns out that wasn't the case, and there was a whole shitstorm because you can't just not pay people and expect to have a place and utilities. So fuck my credit rating and reputation, thank you very much.
I would never move in with someone like that again.
I also lived with a low-level drug dealer once. He was actually one of the beter roommates! He always locked the door, his guests didn't hang out in the common area, he always paid his bills on time, he was polite and friendly, he always washed his dishes immediately after cooking, he didn't listen to loud music or TV late at night, it was pretty great.
I had another roommate who was a gay guy. He (unofficially) lived with his partner who cross dressed but identified as male. That guy was super cool! Sure, there was stuff like learning about how to apply makeup to deemphasize cheekbone contours. We talked a lot, particularly late at night :-p But he was also just a genuinely really cool good person.
It's hard to find a good roommate. I'm content living alone for now.