I have always been fond of these old rock type instrumental tracks from the AIX 2.0 mod for Battlefield 2 (If I remember correctly, it's best enjoyed BF2 only patched up to 1.41), I grabbed the files straight from the game a while back and have just kept them in a folder on my desktop ever since. I think they actually had a thread on the forum about where they shoved all the music in the mod, seems they also said it was composed by a couple members of their mod team just for AIX.
Main menu theme (don't have the file for this one, sorry)
Note: I don't know what file hosts are trustworthy these days so hopefully tinyupload isn't a bad one...
Main Map Loading Theme:
http://s000.tinyupload.com/index.php?file_id=32293929657436987094
Loading theme for map with A-12 fighters (like a blackbird with weapons) and jets from the Clint Eastwood movie Firefox:
http://s000.tinyupload.com/index.php?file_id=36363534596609651575
I can't remember when this one was played:
http://s000.tinyupload.com/index.php?file_id=73761902616695691217
Same for this one:
http://s000.tinyupload.com/index.php?file_id=01612775107389216423
I might look through the old Mechwarrior Living Legends soundtrack tomorrow if I'm not too lazy.
Ooooohhh, you might also like this, it's from the upcoming total conversion for Skyrim called Enderal (same people that made Nehrim for Oblivion).