The Sound Blaster AWE is the best as far as I know. I just have an ordinary Sound Blaster 16, and there is also a lot of good Koan music for that. All versions of Windows have built-in players for the Wav and Midi files, so you do not have to think of that. But you need plugins, a little program to replay the tunes. These players are freely available on the Internet - I'll give you the links later.
Some players are only available as plugins to browsers.
This goes for the Koan stuff. The basic concept of digital recording of sound is called sampling . Here it is converted into series of digital pulses, which eventually are saved in a file. A sample is like a tape recording - it can be good or less good. The recording range from low end, as recorded on the cheapest cassette recorder, to hi-fi recordings in CD quality.