The Sugar Factory is really good. I was initially hesitant because I thought it was going to be a ton of sugary food, but it is actually a great restaurant with delicious food. The people with me had Cheeseburgers which tasted amazing and I had the French Dip Sandwich, also which was really good. It is beautiful at night because you can see the water show at the Bellagio across the street.
They have these amazing, and giant drinks which are colorful and sugary and full of alcohol. I didn't try one, but if they taste as good as they look, I would say that it is a must do while in Vegas. I also love the dark atmosphere of the restaurant.
It is attached to the actual candy store which was fun to look through afterwards, they have a lot of hard to find candy and vintage stuff. Pretty cool place. I wouldn't write it off if you aren't into sugar, as I am not, but it was still worth going to. I will definitely be going back at some point.