www.americasarmy.com

download and install, then do ur training then u can play online, 100% free, designed by the american army, pretty damn realistic(good gfx too depending on ur system e.t.c) first person shooter requires lots of tactics and team play, 100% free too, im addicted to it lol

2.7 comes out soon cant wait for that, gonna get more maps, more weapons, vehicles and an A.I(so u n 8 others can play against an A.I(artificial inteligence) team that react randomly but also react accordingly to your tactics at the time, basically like playing against sum1 else online.