Heard of all of the above, played AoE II, Battle Field 1942, and Medal of Honor.
I can't really say which one is best because they're all different.
MoH is the best csingle player 1st person shooter,
Battle field 1942 in the best multiplayer 1st person shooter
AoE II is the one of the coolest strategy games ever, but I think Starcraft rules all.
Gotta love the terran marine unit, it rocks. (Yes suh!)