That's not the only one, of course..I plan on re-visiting the Half LIfe series (one of my all time favs), along with Far Cry 2(only tried 1). Those are just the immediates. I was a DIE HARD COD fan back in the day, so I'll be picking up where I left off on those as well! (which would be COD3).
As far as I remember, CoD3 was a console-only game. And it was terrible. CoD4:Modern Warfare was good, but short if you didn't do the multiplayer. CoD:World at War was not well received, and CoD:MW2 has no dedicated servers, so if that's important for you for multiplayer, then steer clear.
Personally, I still like CoD1, but the others... not so bothered about.
And Far Cry 2... nothing like the first. Very, very repetitive and samey.