I guess I've played or own just about every good first-person shooter game. All of the MoH editions, most of the Battlefield 1942 editions, the Clancy games and so on.
However, none of these come even remotely close to Call of Duty. This is the current gold standard IMHO, especially if you are into WWII infantry combat games. When TechTV reviewed it they offered one over-riding comment. "Buy this game!"
Call of Duty was developed by Infinity Ward; a newly formed studio including 22 of the individuals, and all of the production leads, who developed Medal of Honor: Allied Assault.
Don't forget to pick up the expansion pack too.
My regards,
Widewing