I’ve barely played the game, it wasn’t for me, but I fell instantly in love with the Bastion and Transistor soundtracks the moment I heard them.
It is my second most played game soundtrack right behind the metal songs from the Alan Wake series. Third is all 3 Hell March songs from Red Alert series. Fourth and oldest is probably Unreal Return to Na Pali and generally all of the two Unreal and four Unreal Tournament game tracks. And the Frozen Synapse series and Uplink soundtracks is probably close to the top too. And I don’t know if it counts but the artist behind the Wheel of Time game soundtrack released a separate almost-soundtrack, which I played A LOT while reading the book series.
And thats just a few of my favorite tracks. I love video game music! I can’t really decide on a single best one.