Wow, I am floored by all of the bad reviews....I've never had anything but fast, friendly service and tasty pizza here.
Bonanno's is very similar to Sbarro - the pizza is pre-made, then sent through the oven again when you order a slice. You can also order whole pies, which are made fresh (takes a bit longer).
They also have salads and pastas, which have always been good when I've tried them. They have a pretty decent selection of pizzas/toppings.
The prices are pretty high, but that's to be expected at a Strip Hotel. They are open pretty late, which is great for after concerts/shows or a night of drinking.