Probably the one that is playing when Soundwave is teleporting Arcee.I have no idea what it's called ,though.
This, as well as the one that played when memory-restored Optimus and the crew walked through the Space Bridge back to base.
"Battle in the Energon Mine" and "Dogfight" are awesome. Dreadwing's theme is chilling, very "horror movie" stuff.
Those are among my top favorites.... Dreadwing's theme is dam awesome. I'm a bit disappointed though, because Unicron's theme is not in here or any of the music from when they are inside Unicron. The music from the 2 last episodes of season one was beyond epic... Hopefully they give us more in the future.