I loved Turrican 2, er, too, but my fave track from the series is level 5-2, in the first Turrican, where you fight Morgul. Chris Huelsbeck is a genius.
I'm also a big fan (and multiple times kickstarter backer) of Matt Gray, of C64 Last Ninja 2 etc fame. If this weren't the 16-bit forum, I'd go for this latter game as my favorite game music, especially the tracks for The Sewer and The Mansion levels.
Honorable mentions: Pursuit - Cornered from Phoenix Wright Ace Attorney DS, Turbo Out Run C64 (Jeroen Tel), Cybernoid 2 C64 (also Jeroen Tel), Tusker C64 (Matt Gray)