Aged goat cheddar on a cheeseburger is pretentious - but lucky for me, I adore pretentious food.
Holsteins is fantastic. I read that they specifically created the restaurant for the Cosmopolitan, which I'm assuming is true because they both have a very cool, similar vibe.
The alcoholic milkshakes are amazing (try the Oreo - it comes with Bailey's) and the popcorn that comes on the table is magical. I don't know what their secret ingredient is but I need to find out.
My only complaint (and not even that) was that there are flat screens everywhere showing football games. My boyfriend was glued to the screen, which was great for him, but made me slightly annoyed since I don't care for sports.
There are also endless options for how you want your burger. Being a cheese snob, I had to go with the stinkiest ones possible - it takes burgers to the next level. I opted for a regular beef burger but the lamb burger sounded amazing - can't wait to try it next time - because I will definitely be back.