Mandalay Bay is good and the Wax Museum at the Venetian is not too bad. My husband and I bought a tourist pass that got us into several of the attractions. Ask at the concierge's desk about them. We paid like $65 per pass but it got us into over 20 different places and saved us quite a bit of money. There are several different types, ours had to be used all in the same day...bit busy. Lol!
I'd also HIGHLY recommend Del Monico's (Emeril's place) at the Venetian. That is also my favorite casino... They have excellent food and we have been there for both lunch and dinner. The Pepper Mill is a little coffee shop type place but it's a good choice for breakfast.
You will be hardpressed to find a bad place to eat in Vegas!