Nicest- Will Ferrell. Met him at a charity event, super nice, funny but not over the top outrageous like his characters. His wife was very nice also, but quiet, not nearly as outgoing as him.
Nicest- Ed Robertson, lead singer of Bare Naked Ladies. Had dinner with him at an event. About as low key as they come. Very sweet, talked about his family a lot.
Rudest celeb- Henry Rollins. Sat next to him at an airport. Asked for an autograph, since my husband liked his "music" back in the day. Guess he was having a bad day, cuz he tore right into me. I never asked for another autograph again.