My brush with greatness occurred in early 1996. I was at the monthly book fair at the Russell Hotel in London. I collect C.S. Forester and was in the middle of campervanning around Britain for a year, looking for deals.
So there's this guy who looks a lot like Michael Richards, just browsing. No one was paying any attention to him (I don't even know if Seinfeld was showing in Britain at the time) and he was apparently alone. He was a lot shorter than he seems on TV (OK, I'm 6'6") and there was quite a bit of grey in his hair, but I was practically positive it was him. And lucky me, I remembered his name.
So I sidle up and say "Hey, did anyone ever tell you you look like Michael Richards?" That's when Kramer chuckled. :) He was probably happy not to be accosted with "Kramer!" for once.
And that was the highlight. Instead of a) just leaving him alone, or b) actually treating him like a normal person and asking what he was looking for (who woulda known that Kramer was a rare book collector??), all I could do was ask for an autograph. I am such a moron.
He said "Quickly," and somehow I managed to find a pen while he stood there impatiently. He signed a pretty elaborate autograph, something like "Greetings from Michael Richards, Kramer from TV's Seinfeld", but it wasn't personalized. And then he left.
I decided afterwards that he wasn't one of your "nice" celebrities, and I didn't even hang on to the autograph. But I've got one on the rest on you--I made a member of "Seinfeld" laugh, instead of the other way around. :)