The Buffet at Bellagio has a wide variety of different food, and decent quality. A little pricey, but the food isn't bad. For this price however, I think I would try to visit another buffet that provides similar service.
If I had known about the 2 for 1 buffet pass, I would say that is extremely worth it but I had not known about it. Don't forget to use your players card, as sometimes it will give you discount and they will also credit tier credits to your profile!