a website I recently found

The homepage of On Classical:

http://www.kunstderfuge.com

It's a resource of classical MIDI files with a small but growing library of
MP3 and WMA recordings. There's a greater emphasis on fugues here as well.
Some of them are already tuned to a historical tuning (Bach's Well-Tempered
Klavier in Werckmeister III, for instance, and there might be some early
music in meantone), but most MIDI files can be retuned with Scala anyway.

The nice thing about this website is that unlike the Classical MIDI
Archives, there's no download limit, and you don't have to register your
e-mail address. I recommend Bunji Hisamori's sequences of Beethoven's piano
sonantas and Chopin's third piano sonata (but not his second). Many Bach
compositions sound really good in meantone, the ones that don't end up with
wolves anyway.

Unfortuately, many 20th century works aren't available because of copyright
issues; only public domain works can be downloaded. Also, it doesn't have
anywhere near as many files as Classical MIDI Archives yet.

(I am in no way associated with this website. I just like it a lot.)