Lost Odsyssey. My favorite soundtrack of all time and Nobuo Uematsu's best work in my opinion. There is so much variety (instruments, moods...) in it and it goes well with the cutscenes and gameplay - I never get tired hearing the normal battle and boss battle themes. 
My second choice would be the Halo ODST soundtrack. Don't get me wrong, I really like the music of the original Halo series, but the ODST soundtrack goes in a different direction and still has the "Halo effect" - that's really cool. It surprised me when I played this game for the first time. This track [http://www.youtube.com/watch?v=FBnbJXO4JIk] is a good summary of it.
I also liked Stephen Rippy's version [http://www.youtube.com/watch?v=Z89adFGjR3g] of Halo and, of course, his previous work in Age of Empires/Mythology.
There are more videogame soundtracks I love to hear. One last honorable mention: Guild Wars (Eye of the North) [http://www.youtube.com/watch?v=5rOve2SuLMg].
My second choice would be the Halo ODST soundtrack. Don't get me wrong, I really like the music of the original Halo series, but the ODST soundtrack goes in a different direction and still has the "Halo effect" - that's really cool. It surprised me when I played this game for the first time. This track [http://www.youtube.com/watch?v=FBnbJXO4JIk] is a good summary of it.
I also liked Stephen Rippy's version [http://www.youtube.com/watch?v=Z89adFGjR3g] of Halo and, of course, his previous work in Age of Empires/Mythology.
There are more videogame soundtracks I love to hear. One last honorable mention: Guild Wars (Eye of the North) [http://www.youtube.com/watch?v=5rOve2SuLMg].