XS is without question the best club in Vegas. I have been there repeatedly with the last time being over new year and every time I go, its always a lot of fun!
What I think XS has over other clubs is:
* Reputation - XS has a reputation of being fun and crazy. I think that it draws those crazies looking to party hard.
* Best DJs - The flip side is that because of their reputation, XS attracts the best DJ period. I have heard several awesome DJs here and they change it up frequently. As many times as I have been here, we have yet to have a repeat.
* Location - I think being in the Wynn with the other top clubs (Tryst and Surrender) in Vegas helps out a lot. Wynn and Encore even though by day seems like hotels for old people... by night, it nothing but clubbing d-bag and young hotties.
* Layout of the club - the layout of this place is perfect. Dance floor in the center with tables and little places to chill extending outward in repeating half circles. Bars on the outer circle to get drinks.
* Club Goers - I have already mentioned it, but the girls that come to XS are usually on different level than other clubs. The chicks are dressed to impress and way hotter.
The only drawback to XS is there aren't enough bars or places to get a drink in my opinion. They only have 2 main ones in the back on opposite ends. Just a minor gripe. Nothing tops XS and I will definitely be coming back in my future trips to Vegas.