This is my go to lounge when on the strip. It never ceases to amaze out of town visitors and is the perfect sippin spot pre-Marquee partying.
It's 3 levels but the best is 1.5 (the middle level).
The GM and head Mixologist Mariena Mercer is fantastic. She's always coming up with creative cocktails such as spirit snow cones which I recently did a feature story on CitySip.com.
A must try cocktail is the Verbena. It's not always on the menu so be sure to ask for it.