I've met one and seen many.
Biggest that comes to mind was Christopher Lee. I was in London as part of a James Bond tour group in 2006 for the Casino Royale premiere. The first night featured a small party at a supper club, about 20 people, and Christopher Lee was the special guest. He was meant to just be around for an hour, but he was enjoying himself so he stuck around for three hours. He told acting stories. talked about his new (at the time) music album (which we all received signed copies of). I got to briefly talk to him, shake his hand and thank him for all the work he has done. I recall telling him I loved him in Lord of the Rings and Attack of the Clones.
Outside of that, mainly brief encounters and sightings. I literally bumped into comedian Richard Lewis in New York on a busy subway station exit. I sat next to SNL alum and current SNL announcer Darrell Hammond at a diner on that same trip. On another trip to NYC I walked past Anne Hathaway and later that day spotted Macaulay Culkin hailing a cab. Then, a moment later Liev Schreiber was crossing the street with his kid. I swear, New York City is the place for celebrity sightings, lol.
Oh, as a kid I saw Arnold Schwarzenegger and Sinbad filming Jingle All The Way in Minneapolis. They used our school parking lot for film storage.
Politically, I saw Obama as a Chicago senator in the 2005 St. Patrick's Day Parade. I also heard George W. Bush speak at an event as a kid. I hate Bush, but it was cool to see a US president in person. I also heard Joe Biden speak last year at an Amtrak event, I was in the fifth row.
I've actually never really gone to concerts and don't consider them to be meeting a celeb or a sighting, as you're paying to be there. But I did see nearly every Tim & Eric live show that passed through Philadelphia including their first show before they hit it big. I also caught a Ricky Gervais conversation at NY Comedy Week 4 years ago and was lucky enough to catch the Kids in the Hall live tour.
On the gaming end of things, there are all the Swingin' Report Show interviews and the NYC Sonic Boom event where I met Sonic Team members and voice actors.
