I'm not joking, it's atleast the best classical piece I've ever heard from a videogame, beating Crysis' and FF8's entire soundtracks.

The song is 9 minutes long, and Do Not Skip a single second of it. Just run it and let it flow into your head while you're browsing VGchartz:

One single word: EPIC!! (it also gave me a star wars vibe for some reason)

Bleh, I'm not getting into that again. World of Warcraft sucks your life away. You love it while you play it, but when you stop you realize that you weren't actually happy.

Edit: The music is good though.  I listened to it a few days ago.  Definitely sticks with the Warcraft style. 

The best OST in a video game goes to Baten Kaitos and Baten Kaitos 2 hands down. They have an amazing soundtrack that really surpasses anything else heard in a video game. Secret of Evermore for the SNES also has some beautiful musical pieces, though not of such high quality given the storage limitations.

Meh.

Here's a better song.

 http://www.youtube.com/watch?v=PGnWn5WXuCo

The best video game music of all time imo, has to be Lineage 2. (ironically an MMO as well).

Scroll down and take a listen. It's amazing stuff.
http://www.billbrownmusic.com/musicG5.htm

I never heard Baiten Kaitos so I wouldn't know. Personally I'd put FF8, Crysis, Deus Ex, Warcraft 3, World of Warcraft, Mafia as the best soundtracks.

Deus Ex and Mafia's aren't classic music though.

FFIX has the best soundtrack of the FF games IMO, but there are so many games out there with amazing soundtracks. Listen to The Opened Way from SotC up above. Check out Baten Kaitos (not all classical), the Star Ocean Games, Super Mario Galaxy, Dark Cloud 2, and the MGS games as well for great classical music.

Actually, the best music for a video game would be any star wars game, but that's kind of cheating :).

The above SotC music is great by the way.

Ah yes, I'd put SMG's near my top preferences. No way in hell SotC, Star Ocean, DC2 or MGS games though. And in FFIX you could already see uninspiriration from Uematsu, FF8 was his biggest work Imo.