That's a great question, and we'll do our best to answer, but we confess that we've barely had a chance to hit the pool scene for a couple of year now (shameful, we know), with the odd exception, so what follows will be a combination of some personal experience, trusted reports from third parties, hearsay, and common sense/guesswork. If any reader feels we've missed the mark on any pool scene, please drop us a line with your reasons and we'll investigate.
It's been a few years since the concept of "daylife" reared its head and now there's a virtually seamless summer party scene, as day blends into night and into day again, and revelers migrate from the pool to the club to ... The pools pull names just as big as the clubs do -- in fact, often a resident star DJ will play at a different pool during the day, then hit his club at night -- it's like a game of musical turntables out there and some scenes get really wild. As we realize that's not what you're looking for, so if you take a look at the gallery of happening pool scenarios in our Cool Pools feature, we'd say off the top you can steer a wide path away from Rehab at Hard Rock, Wet Republic at MGM Grand, Liquid at Aria, Palms Pool, TAO Beach, Sapphire Dayclub, and Daydream at M, which are all catering to a raucous younger crowd, on the whole.
Still, you may be 30 (that's "old" now? yikes!) but you're not dead, so some of our suggestions for catching good current music and a fun, sexy, but more mature and less outrageous crowd would be Artisan's Naked Pool (it's "toptional," so bear that in mind, no pun intended), similarly Bare Pool Lounge at Mirage, which is topless but featured a broad span of ages having fun, but not getting stupid the last time we were there, which was a couple of years back.
Cosmopolitan has a cool pool complex, and we've heard good things about Marquee Dayclub, which is the most party-centric of the three. If it's too hectic, retreat to the mellower Boulevard Pool. Mandalay Bay is famous for its white sand and wave machines, and it's definitely an awesome pool if you're looking for water activities. There's poolside casino, plus the option of retreating, for a hefty fee, to the more refined atmosphere of Moorea Beach Club (topless), for a fee.
Caesars has a massive pool complex that features something for everyone, from swim-up blackjack to DJs to a adult-only chill zones, plus it's home to Las Vegas first-ever topless pool; we figure you're bound to find something that suits your mood at the Garden of the Gods.
Stratosphere's "8" is open to hotel guests only this year, according to the last we heard, which is a shame, as it's another pool that's not as crazy as Rehab, but still features lots of fun activities including beer pong, blackjack, volleyball, and so on. Give 'em a call if you fancy checking it out and see if you can chat your way in. Gossip, the pool at Artisan's sister property Rumor is, like Naked, a smallish and intimate set-up, but it's not topless and the hotel is both dog- and gay- friendly, so you know it's a fun spot!
Lastly, if you're downtown, you can't go wrong with the Tank at the Golden Nugget, which is another of those, "Something for everyone" set-ups, including an aquarium and shark tank that you can slide through, poolside gaming, a small discreet topless area, lots of lounging opportunities, and an adult-only pool. Check it out!