COD MW2, COD MW, COD black ops, BF2 badcompany, BF3, Crysis, Crysis 2
just for starters.
Resistance 3 is an aquired taste. Homefront, killzone 3, farcry 2 (decent but not great for everyone)
You could also try sniper ghost warrior and sniper elite v2, although they are third person, they are epic shooters!!