In the documentary "The Last of the Blue Devils" Count Basie says he'd just like to be remembered as a nice guy. I was reminded of that reading the interview with Bob Cranshaw who certainly seems to be a nice guy and the story he tells of Milt Hinton's generosity is pretty mind-boggling. Given that many of our musical heroes appear to be less than stellar in other aspects of their lives which jazz musicians do you know or know of who seem to be genuinely nice guys? I'll start. (Obviously Miles doesn't make the cut even though I love his music.):
Count Basie, Bob Crenshaw and Milt Hinton (see above).
John Coltrane. There's a documentary in which Elvin Jones describes Trane as a saint. He says it with such reverence it made me love Elvin too.
Gil Evans (though I've read that his mellowness was the result of a lot of weed.