I'm pretty sure this game is still in Beta, but it's amazingly fun in my opinion. Similar to CoD/Halo style of play, with the addition of numerous humiliating teabag style moves you can use on your downed opponent post-kill. Also shooting people in the penal region grants bonus points! Very fast paced with big and small maps. Free for All, TDM and Domination
http://www.offensivecombat.com/Play.aspx
http://www.offensivecombat.com/Play.aspx