I still think nothing has come close to the final fantasy series. mass effect being the closest

There can only be 2 answers:

Shadow of the Colossus
Journey

Every video I find fucks up the flow by going into bonus levels but listen to this:

Playing a stage in Donkey Kong Country (Snow Barrel Blast) where the level starts off calm and then a blizzard slowly builds and then recedes.  When I played this game back when, I couldn't imagine it getting better than this.

As for more recent examples, I'm drawing a blank.  Everything is kinda squoosed together in my head.

Rayman Origins.

The platforms you bounce on add percussion or other things to the overall sound, because they're in the key of the song.

There are other games with better soundtracks imo. But Rayman Origin's "Wove" it in better than any other.

How is music woven into their gameplay...? I'm thinking you're confusing this with a 'which game has the best music' thread.

OT: Elite Beat Agents! :D

Grand thetf Auto Radio stations and my xbox hardrive

Pretty much all Rareware titles qualifies in my opinion. Robin Beinland always came up with (well, and still do as he is still working at Rare Ltd) the most amazing tunes for all their games. They all fit perfectly to their levels' themes and always got stuck in your head :) (Especially the Banjo-Kazooie tunes.) Not to mention the feel of flying sky-high for the first time in a Banjo title while the level's tune slowly gets replaced by nothing but the sound of the wind.

Good times.

I think the soundtrack in Heavy Rain fitted the scenes and the moods perfectly and the QTE were often cleverly embed with the music.

How is it that everyone's answer isn't the Dreamcast classic Rez?

Fear is the mind killer...