Combat Arms
AssultCube
WolfTeam
Wolfenstein Enemy Territory
Tribes Ascend
Ghost Recon Phantoms
UberStrike
UrbanTerror
F.E.A.R Combat
Joint Operations
World War 2 online

All of the games above are free FPS with the exception being GRO cuz its a TPS

The game that I think you would like the most, is Soldier Front 2. Its on Steam and its free. Its a FPS but its the only game I know that has MOBA elements mixed in a FPS game.

A other game you should check out, is Defiance. Its a free TPSMMO with some MOBA elements.