Valve Showdown! Half-Life vs. Counterstrike!
I'm not really into videogames. Counter strike is the only FPS I've played, because I have a couple friends who used to. I was shit
Half life although.... WHERE IS EPISODE THREE????
Half-Life 2 >> Counterstrike
Half-Life, specifically 2, revolutionized a lot of what games were, with it's embracing physics as well as certain graphical/audio things it did. (Also was pretty fun when I was a kid.)