Big fan of Celtic
I love Celtic music..great Question..I would try out Pandora, and type in the search bar, In Dreams..or Nightnoise ..these stations have amazing Celtic music-mostly intsturmental though . Also, if you type "Lord of the Rings" into it, it will play Enya, and various Celtic bands too (besides the LOTR music, which is amazing ) :)
who's your favorite so far?
Im more familiar with traditional celtic/renaissance, like hammered dulcimer and such. If you are curious about that, check out Arlen Olesen. He and his family/friends put together an album 'Da Caald Nights O Winter'. Good stuff. Though I do enjoy Cherish the Ladies =)