I can not find a good review with starcraft 2 as the benchmark. A person wants me to build a computer for them that can play starcraft 2 on high, 1080p for the cheapest possible option. I don't think this is enough, but maybe with a 6670.
Natural Selection 2 (NS2) - FPS/RTS with depth. Link
Studios and publishers seem to have forgotten that games are supposed to be games, not CG films with playable action scenes. Link