One of my favorite lounges in Vegas.... And it's not even a big time or main stream lounge to begin with. Located in the heart of the MGM Grand is Centrifuge. A circular lounge comprised of a round bar and booths/lounge seating around the perimeter. The bar itself is artistic which has LED lighting, bottles wrapped around the backing, TV's surrounding the top and an artistic moving object above the entire lounge (hard to describe).
So why is this my favorite? Well, it's because of the bar staff. I've been coming to this lounge for the past 4 years and each time I've gone, Lora has been my server. She's cute, super nice and loves to be social. She makes all the difference for me.
She also allows my group to sit at the VIP booths which are reserved for bottle service.
The go-go dancing is also nice too which seems to happen every half hour... =)