I have done some crazy role play sessions! I took some acting classes, so it's always a blast for me as long as I know well in advance. For some reason, it's easier to do with strangers! I don't know that I could do it that well a regular. I'd probably start to get all embarrassed.
I think the best/worst role play session I had was acting out this scene where the sub wanted to be "pretend" drugged, kidnapped, interrogated etc. While we were acting out the scene I kept telling him that I had put something in his drink, taunting and chiding him. He actually really got scared! He got so scared that we had to stop and I had to convince him he was okay. We were having a lot of fun until then
Crazy how powerful and easily our minds can be messed with.