I agree that Kaplan is the best celebrity player. He's crafty and unpredictable, and can hold his own with the big boys.
Tilley doesn't just play a ditz, she is one.
Phil Laak is a much better player than he gets credit for, because he undercuts it by being wierd. I didn't think much of him the first few times I saw him play. The first time I saw him play, he was seated between Brunson and Hellmuth and seemed totally outclassed. But now that I've seen him more often, my opinion of him has risen, especially when he is interviewed on Poker After Dark, and you get some insight into his thought process.