http://combat.sweetspotgames.ca
I developed Combat for one of my previous employers, Sweet Spot Games. The site featured real-time rankings, a leader board, a messaging system, a feature-rich administrative portal for user/site management and a store front allowing users to redeem their in-game points for real-world prizes.
Sadly, the game hasn't yet attracted investor capital and remains more of a proof-of-concept for a first-person shooter with a large, persistent world.