Met quite a few (although to be fair it's pretty much the norm if you live and work in central London)!
Amy Winehouse circa 2003 in the Barfly in Camden. She was standing at the bar with a group of mates taking up the only available space for anyone to get an order in. She was very drunk. Refused to budge so I literally had to lean over her and yell at the barman and stand on tiptoes to collect my drink. I would have liked to argue with her but there was one of me and about 6 of her party so I deemed it a waste of time.
Jools Holland smoking outside London's Savoy Theatre last October. Very rude. Asked him for an autograph and was given a brusque "no", after which he promptly turned away and discarded the ciggy then went back indoors.
Chantelle Houghton walking down Oxford Street about 2,5 years ago. Very friendly and smiley.
Abi Titmuss in Office on Oxford Street summer of 2006. Really nice actually, seeing as I expected her to be bitchy and stuck up.
Pete Burns December 06 in Oxford Street's Topshop. Walking several paces ahead of his boyfriend, looked like they'd just had a tiff. Never liked the guy and thought I'd try to annoy him by asking for his autograph, to which he yelled "no!" and continued storming off.
Mark Hudson in Pret A Mange on Oxford Street, same day as the Pete Burns sighting (lol the stars were out to get me that night). Very friendly and signed his autograph for me.
Jerry Sadowitz walking down Clarkenwell Rd, 1999. I used to watch his show otherwise I would have had no clue who he was. I stopped him and said "hey, great show!". He forced a really weak smile then went on his way. Odd guy.
Ville Valo (lead singer from HIM) in The CroBar in London's west end, about 3 years ago. Completely inebriated. Didn't ask for an autograph because I'm not a fan of his band, plus he was acting very uncouth.