I live with three other guys.
I myself am the slob of the group, honestly. I'm disorganized, always frantic, and a bit lazy. Ironically, I also clean the kitchen the most, do my laundry the most, and clean up around the house the most. It just so happens that my clothes are all over my floor, I have soda cans piled around my computer, and I usually leave my dishes in the sink to be cleaned up a day or two later.
Roomie #1 is the socialite of our group. He's always out meeting girls, and--to my chagrin--bringing them back to the house. He's fairly clean, but a complete gearhead (meaning he's into motorcycles and anything with a motor and wheels). He's what he terms as "a normal red-blooded male," which is apparently an excuse to swear and live a lifestyle of promiscuity. He's a fighter, not a lover, and there's nary a romantic bone in the man's body. I, being the romantic of the group, am emotional. I wear my heart on my sleeves, am very open and honest, and this guy is the exact opposite. He's honest, but very shut off from everyone, and doesn't even allow his girlfriend to tell him that she loves him. He's insecure, but he hides it under a shell of machismo.
Roomie #2 is a bit like me, but more "together" given his longer life experience.
Roomie #3 is the drama queen that drives me up the wall. You ask him how his day is, and he's never "good" or "bad." It's always, "the worst day ever because of his <insert long string of expletives that he uses> ex-girlfriend that won't leave him alone."
How do we all co-exist?
2 Timothy 2:23
Don't have anything to do with foolish and stupid arguments, because you know they produce quarrels.
Pick your battles. Don't offer unsolicited advice, and try to learn something from and/or about your roommate every day. Keep conversations short if necessary, stay out of each others' way, and do the best you can to be civil, if not friendly.
Roommates are often a temporary thing, and you find that their qualities (good or bad) can rub off on you. Be aware of that, and do your best to let the good rub off on you, and the bad just fall off of you.