Mannheim Steamroller is an orchestra that remixes christmas songs into awesomeness, my favs from them are Hallelujah, Angels We Have Heard on High, Los Peces en el Rio, Good King Wenceslas, Rudolph, Still Nacht... it goes on.
I dunno what file format you're talking but I have 500 wavs and wmas that are a mix of the best stuff I have found. It's got lots of variety, and all of it can be downloaded from Youtube, so p sure it's all free (most of it has never been released in the music industry anywhere). Lots of stuff from the soundtracks of following games:
Super Smash Bros (melee and Brawl), Cave Story, Cave Story + (wiiware, EU and fixed NA 1.1), Cave Story 3d, six tracks from the Cave Story beta (Wind fortress is much much better in the 3ds remix but the beta of Opression is almost a completely different song), Wario Land 4, Half Life, Half Life 2, Portal, Portal 2, Vectorman, Vectorman 2, Hexic HD...
It goes on. Tomorrow ima zip the whole lot of em and upload em to Dropbox. I'll PM you the link if ya want it.