I was in Vegas in 2004 and I remember the biggest buffet with the widest variety of food being at the Alladin.
During that trip, I ate at a buffet nearly everyday, but I soon discovered something strange: certain foods tasted the same at each buffet. For example, the mac & cheese, the chicken fettuccine alfredo, the meatballs, the french fries… all the same! A friend who worked at one of the shows there later told me that all the buffets use the same catering services/chefs, which is why certain “staples” tasted the same in each place!
With that said, the Alladin still had the best buffet because of the size of the buffet. They divided it by cuisine: Chinese, Mexican, Italian, Japanese, etc. Needless to say, trying a little bit from each cuisine left me overstuffed!
Things may have changed since 2004, so keep that in mind.