Deep inside the Cosmoplitan the Vespa bar is a cocktail partakers dream. The variety of cocktails is impressive and you can order off the menu and have one the bartenders mix something special. This place is not a bargain, the cocktails are priced steep, but very tasty.
I have tried a few different cocktails and generally all of them have been very good. If you don't know what you want or can't decide, it's easier to to tel the mixologist what you like and have them go wild.