Assuming you mean housemate and not roommate I definitely prefer to live with one or two friends. I would never live with random people and I tried living with 6 other friends before and then 4 other friends before and it was just too many people and even though we were all friends we still fought because you can't have that many personalities together and expect everyone to get along 24/7. Just not possible.
Best situation is what I have right now. A house with 3 separate floors with separate entrances. Me and my friend have the basement apartment & the floor above us is 3 more of my friends with a lockable door between our apartments. We can party hard when we want to or we can be solitary. Noise complaints are moot because we just talk to each other (or gang up on the dicks on the top floor) and the cleanliness isn't a problem because me and the guy on the bottom are the cleanest and the mid floor all are happy with how clean their place is. A-M-A-Z-I-N-G.
Also, on the subject of wanking it - who cares if someone in the room next to you is doing it? As long as it's in their room and he/she keeps the **** volume down I say go to town! I probably wouldn't high-five them afterward though... cause you know
If it's roomies then you just do it when they aren't there and put a sock on the door! Sure, it may be solo luvin but luvins is luvin baby