i love the old snes soundtracks,like the music in terranigma. I'd definatly go with odst. but a moment that was affecting me very much was at the end of portal 2 where the turrets start singing . that was amazing.also the music in okami made the game even more special for me
The Orchestrated Soundtrack CD that came with 'The Legend of Zelda: Skyward Sword' Defiantly amazing to hear all those old Tunes redone with the use of a Full Orchestra Especially the Gerudo Valley Theme: www.youtube.com/watch?v=THdRs7grqhE (The Louder you set the Volume at, The better It Gets)
The Halo series has had amazing soundtracks through all the games.
However, I will have to hands down say that the best video game soundtrack ever would be Skies of Arcadia for the Dreamcast. It's also one of the greatest games of all time as well (super underrated).
Always have loved the Zelda and Halo soundtracks. However the Splinter Cell: Chaos Theory soundtrack has always stuck with me. I think its just really well done in the sense that its effective. The sneaking music is calm, yet gives off a sense of danger and being on the edge. And the action music is effective yet not over the top. For a game that came out in 2005, I am still impressed by it.