Songs can easily have no words, for instance all of the Liquid Tension Experiment songs are without words, and yet many people still like to listen to them.

I've always found AoE to have some interesting songs, but I found their in-game music a little more slow and in the back-ground.

Lords of the Realm II must have some pretty good tracks.

Of all the games I've played, the one that would probably rate closest to this would be Halo. In addition to that the original C&C and Tony Hawk 2 had some good tracks.