I met Jim Bowen as we booked him for a works sales event - He was great, smashing,marvellous.
Seriously, a really nice, down to earth guy. I was the only person at the event to ask for his photo/signature, I was disgusted at the other people!
Bear Grylles (is that how you spell his name) - great guy, very polite
Chris Hoy - also really nice guy, he was just getting used to his new found fame at the time and you could tell he felt a little embarrassed by it all.
Various Rugby and Golf stars due to sponsorship work with my employer. Every one, without exception, were straight up, approachable guys who weren't self absorbed.
Princess Diana (before she was a princess) - lovely but very shy
Oh yeah...also Mark Lamaar....enough said.....