Ape Escape soundtrack is really good, it's got a breakbeat style all the way through
Golden Sun had a pretty awesome OST, unfortunately somewhat gimped by the GBA's sound quality.
Stewart Copeland's
Spyro the Dragon's soundtrack will always be one of my favourites of the PlayStation era.
Bit more obscure,
Jumping Flash! 2 had a couple of really great tracks, RIP Takeo Miratsu.
Not sure how many people ever played the original, but I've always loved the OST from
Dynasty Warriors :3
Since you posted Rayman Origins, I feel it is my duty to post
this from the original.
There's so much more to post, but I'm not going to flood the thread, haha.