I've been thinking of more historic personages that might be interesting over dinner. Right now I am considering Voltaire and Cicero as potentially very interesting dinner partners. I'm also considering Thomas Jefferson, who would make a very nice counterfoil to Voltaire, and because of his very strong classical education would also have much to say to Cicero with respect to republican (Roman) politics.
Edit: I've also been thinking of some of the nastier suggested personalities such as Hitler, Stalin, add Sulla, et al. and I've come to the conclusion that I really couldn't enjoy eating with them. I think a debate style meeting, where you could ask questions and then listen to them explaining themselves with a stop watch to limit their responses would be more appropriate. Hitler for one was known to get into rants. that does not make for a pleasant dinner. Debate, maybe. dinner -- never! Also, he was a vegetarian, so that might be a bit uncomfortable at my table.