I don't have a favorite, but I've seen many celeb's, even though I don't live in L.A.! Sometimes when I'm in a restaurant or a hotel, celeb's walk by. It's the strangest thing!
I've seen:
Brad Pitt
Matt Damon
Keanu Reeves
Michael Douglas (3 times!)
Harrison Ford
Paris Hilton
Danny Devito
Robin Williams
Woody Allen (twice!)
Laura Linny
Olivia Newton John
Christian Slater
Liam Neeson
Denzel Washington
Don Adams
Mario Cantone from Sex and the City
Sarah Ferguson -The Dutchess of York
...and MANY others that I can't remember! Isn't that weird??!