This hotel is excellent but the restaurant is darn near terrible. Breakfast is fine and consistent with other Marriotts, but the bar/restaurant has bad food and lazy service.
Tom's is two blocks down Jefferson and is very good, especially if you like seafood and a good wine list.
The J.Lohr is a good deal by the glass at the hotel bar.
There's an asian restaurant upstairs on your way to the breezeway to the GM center that is good and cheap, but doesn't serve alcohol. Take out for your room is easy from here.
I tried Andiamo's across the street on the river and was underwhelmed by the food I had. The view is gorgeous and the restaurant is nicely decorated, quiet, and the service is good. Wine is very pricey though, so get there before happy hour ends for half price wine by the glass.