For use in-game, the OGG and MP3 soundtracks actually sound about the same, but OGG loops properly, so it's recommended.
The PSF format is exactly as it sounded in the Playstation game: better than the crap midi in the PC version, but nothing special either. Personally, I think the remastered soundtrack is better so that's what I prefer to use, but if you're a purist then the PSFs are what you would've heard on the playstation back in 1997.