This is the best free pool on the Vegas strip! The pool is free for hotel guests and charges about $15 for non-hotel guests. Drinks are reasonably priced at $35 for a bucket of beer (free beer Fridays includes an extra beer for free) and $16 for a specialty cocktail...which the bartenders make very well and strong! Get a pink cup and bring it back for refills. It's cheaper though to just order the specialty drink in a cup and pour it in your cup yourself.
The atmosphere is very chill including the people. There is a grotto area and even a few areas of shade around the pool. The palm trees give it a tropical feel. They usually have a DJ and on weekends there are contests if you choose to participate, winner usually gets a $50 bar tab.
Chairs are often hard to come by so I'd suggest get there early to snag your spot. We've been here several times and have never had an issue with leaving our stuff. We continue to visit Vegas at least on a yearly basis and this pool is one the reasons we stay at the Flamingo!