I always spend a lot of money when I visit this store in Las Vegas. It's 3-4 stories high and each floor is a treat. They dedicated one wall with tubes full of multicolored m&m's. They have interesting little rooms - some with stories about each M&M character & one walk-through room showing how M&Ms were made.
Recently, they came out with some M&M Premiums (5 flavors - Mocha, Mint, Triple, Raspberry, and Almond). Not only are these delicious, but they're beautifully colored.
The only thing that bothers me is how crowded they always are, but I guess that's expected!