A lot of gaming coins out there each do something a little unique but each are trying to integrate gaming in some way. You can check out the following gaming projects
1) MobileGo
2) GameCredits
3) Storm
6) Digibyte
4) 1st Blood
5) Nexium
7) WAX
#8) Enjin
9) 1337 and more
Good list, I think firstblood is the best project in the list but it is rather a specific project. digibyte could be used in many games independently as it is very fast and decentralized.