I guess I play Lawful Neutral. I usually won't start trouble or look for it, but if attacked or I feel the need to help because I can, I will. Raiders you usually don't have a choice with. Legion are tough and seek revenge, so I try to just stay away. BOS, I guess I remember their role in FO3, so I try to keep the peace. Just some examples.
I like to try to roleplay a Raider's role, but I always end up the Raider that decided to change their life around and become peaceful. It's hard to roleplay that hardcore and stick to it. The game is set up well for the good guy. You're almost all alone as the bad guy and always looking over your shoulder.