I've met many famous folk in my line of work but a couple spring to mind.
Omar Sharif getting his (very hard fought) battle to take his new lady friend back for a "nightcap" turned down so I dropped him back at his hotel & took the lady home. En route she made me smile with "he may be famous but he's still not getting in my knickers on the 1st date"

Christoper Biggins who was VERY drunk after his last night in panto & all the cast had gone out to celebrate. Now he's got a funny soh at the best of times but when he's totally out of his head he's just a barrel of laughs, had me in stitches.
Arthur Scargill who I took from Brighton to London after a BBC Question Time during the miners strike. I told him I was not interested in politics so could we chat about "anything but" if at all possible & that's exactly what we did, changed my impression of the man for at least an hour or so!
Zoe Ball, just a sweetheart & so down to earth. Another who was completely non pretentious was Richard Branson, an average guy who has made his money the hard way but still remembers where he came from.
Following on from Scunner I took David Walliams home (he lives next door to Zoe & Norm!) a month or so ago, dark glasses & cap pulled down tight, maybe it was the raging hangover at 10am that he was trying to hide but there's no mistaking the smell of a person who has been "on the drink" the night before, he was just grumpy!
& there's many more...