Rick Bayliss at Topolobampo in Chicago.
Joel Roubochon ( twice) once in Paris and also at Le Atelier de Roubochon in Las Vegas.
Wolfgan Puck at Spago, las Vegas.

And Mario Batali at his family's small but excellent little deli in Seattle - Salumi.

mike

Michael Mina at Michael Mina in Las Vegas. I didn't really know which one he was but he was pointed out in a group of a couple of fellows. So I know who he is among two or three!

Celebrity Chefs
 

Wolfgang Pucks at The Cut.

I didn't see her specifically, however, a co-worker and I ate at Campanile on the first day that it was open to the public, so I assume that Ms. Silverton was there

At Spago on a Saturday night a while back Wolfgang Puck went to just a few tables to say hello and make sure everything was good. The only comment from the British couple next to us was something minor like they needed a fork or a water refill. :D They were surprised when we got his autograph and a picture (what the heck, right). When they asked why we did that and we explained who he was they looked kind of embarrassed but later the woman walked over and they got his autograph too. :p

I really really admire him for doing this unlike Planet Hollywood or Emeril's where I bet you rarely ever see the owners.