Hmmmm....
Hugh Jackman moved into a house down the street from me for the summer while he was filming for a new movie, so I saw/met him quite a few times.
Gerard Butler was also in town filming a movie and I saw him at the bar a few times, plus he would hang out with Hugh Jackman at my neighbor's house and play poker once a week so I would always see them show up and leave haha.
I met Regis Philbin in an elevator on a cruise ship.
I met the Etnies BMX team over the summer when they put on a demo.
I had dinner with Chris Osgood at a charity event and met the rest of the Red Wings team.
My friend's uncle is Lawrence Kasdan ( 
http://en.wikipedia.org/wiki/Lawrence_Kasdan ) and Adam Brody is good friends with his son, so I met Adam Brody through them.
One of my dad's clients is Shane Battier, so I've hung out with him and his family quite a bit, and met some of the other Houston Rockets when they were in town for a Pistons game.
Ian Compton was a judge in a local rail jam this September haha
That's all I can think of for now...