Tom Clancy's Rainbow Six Vegas 2

Rainbow Six: Vegas 2 is definitely a suggestion for everyone who loves a good tactical shooter. The new "Cover and shoot" system brings even more fun gameplay than its predecessor, Vegas, had.

"Rainbow Six Vegas 2 for the PC is the weakest of all the versions due to its poor optimization, broken textures, and questionable AI. However, it still features all the same action and content as its console counterparts, and it's a decent tactical shooter in its own right."