Reading through the Musicians/jerks thread, I thought it would be only fair to play up the other side of the coin. There are also musicians who are good, friendly people.
I'll begin with Roswell Rudd. I've come in contact with him a couple of times, and he came across as a friendly, enthusiastic person with a big heart. Last November, I sent him a birthday card and a week later was very surprised to receive a thank you card from him saying that as long as I was listening, he'd be playing.