Medieval/Celtic music?

I enjoy Medieval/Celtic music. Anything that sounds like it came from the time of knights slaying dragons or bards playing ballads.

Anyone on here know any good websites where I can download some? Or some artists/bands that make some?

The only one I know of is [Sopor Aeternus (& The Ensemble of Shadows)]. I listen to a few other bands that have that kind of music IMO (But only for a few songs), but I don't know if they'd really count or not. ^^;