I grew up on the west coast, so White Castle is a relatively new phenomenon for me. I've been here at least 3 times, and I have to say that it tastes the best after a long night out. This is located in the Casino Royale casino, in between Venetian and Harrah's. This past time we went, we tried 1 of almost every slider available. Here's my personal ranking from best to worst:
Double cheese slider
Original slider w/ egg and cheese
Cheese slider
Fish slider and veggie slider
Chicken ring slider and chicken breast slider
I hope that makes sense. I honestly couldn't tell the difference between the two chicken sliders. The fries are a must here, especially when they're freshly fried. Also, don't forget to ask for all your sauces at the counter when you pick up your food! The food usually comes out pretty quickly, so don't be discouraged by long lines!