What's your favourite video game soundtrack?

[Dim]

I'm looking for some more interesting video game music to add to my library and I thought I'd ask you people for some ideas.

Please just include the name of the game and why that particular soundtrack is special to you. It doesn't have to be from any specific era or console, and it would be helpful to include a youtube link if the game isn't well known.

For me it's almost impossible to pick a favourite but it would most likely be Faxanadu if I had to choose in a life or death situation (I'm not sure how such a situation could transpire...). It's not the best soundtrack in many people's opinion however it made the feel of the game unique as a NES game, nobody was making such frightening and eerie music back then (except perhaps Battle of Olympus) and it also has nostalgic value for me because it reminds me of happy childhood times.

Link: YouTube - Faxanadu overworld theme!

[MentaL]