Depends on where you're staying and what you want to spend, in addition to what kinda food you're looking for.

If you don't mind spending a good chunk of money, Sinatra in the Wynn is literally the best meal I've ever had. It's Italian but legit - best food I've ever had. I know the wine director there and he filled our glasses all nite.

A good Asian fusion place is Jasmine in the Bellagio. Also a really good menu and quality food.