I am sure that I will forget to include some, but here goes:

Kevin Nielen - plane
Tootie from Facts of life - plane
Travis Tritt - plane (and his smoking hot wife)
Vince Neil - airport
Steve Forbes - plane (yes, he was flying commercial)
Craig Stadler - plane
Sterling Sharpe - bar after senior bowl
Norv Turner - bar a few day before senior bowl
Randy from band Alabama - Beau Rivage
Corretta Scott King - airplane
Jared from Subway commercials - airplane (Boom mf'ers!!!!

)
Bill Murray - airport (only time I've locked up and not had anything to say.)
Shaun Alexander - restaurant in Mobile
Chris Samuels - DC airport
Jake Peavy - wife used to work with me. Saw him a lot when he was playing for Mobile Bay Bears
Kenny Stabler - at a George Jones concert and several times at Flora-Bama over the years.
Merle Haggard - meet and greet before his concert in Biloxi
Sarah Palin - outside of a hotel in Des Moines (there is a funny 45 page thread on this with pics)
Richard Tyson - airplane
Tyra Banks - restaurant in NYC
Newt Gingrich - spoke to a few folks about healthcare
Bill from Apprentice - was my company's attraction at a trade show once
Frank Abignail - the real "Catch Me if you Can" guy
Brian Williams - in the pit at Talladega
Christian Yelich - coworker used to be his coach. Met him fb a game in Jacksonville.
Reggie Bush - restaurant in Augusta, GA during Masters

I know there are more, but I can't think of any more right now.

I travel a bunch, so I have a good chance of seeing celebs a bunch. And, I seem to be decent at spotting them, which isn't always easy. A lot of times they do not look how you expect. I would love to know how many times I have passed right by someone famous and not realized it.