OK, just so you know, you couldn't pay me to eat at Tony's again. From the other 2 choices, it would depend on whether this was for lunch or dinner, and whether or not you're on the DDP.
If it's lunch then I'd go for the Plaza. We usually have the DDP and for our tastes think that the type of food served at the Plaza is really more on a par with CS types of food, but at a higher price (in other words, not a good value)
For dinner I'd definitely recommend CP. Of course it's always a matter of personal taste, but our family finds the quality of the food just fine, with an excellent variety. The building itself is beautiful, and the characters (no matter how old you and your family are) are a LOT of fun, with great interaction. It's a no-brainer on the DDP, since it's only 1 TS credit. Maybe a little pricey if you're paying OOP.