Just listen by yourself! I picked just some of my most favorite tracks and even one Medley of an entire game’s music. I even own a 300 games large music archive, and it’s hard to choose the very best. So I took some game soundtracks I’ve listen to right now the most.
Command and Conquer: Tiberian Dawn
Just do it!
Metal Gear 2: Solid Snake
Theme of Snake & Zanzibar Breeze
System Shock 2
The Coolant Tubes