As a side note, I heard from another guy in line who was ahead of me that he was talking on his phone as he was signing books! I can't say I'm surprised given my prior experiences but I've never witnessed such a thing. I would definitely rate him as the rudest one I've come across.
And I should give a nod to the nicest (if I haven't already in this thread)...Matt Damon. Probably the most fan-friendly celebrity I've encountered.