Is the question about albums whose original master is better than the remaster? Or is this about albums where there's an "unmastered" version floating around the 'Net?
Unfortunately, "Remaster" these days usually means just make the original source louder. I haven't done many A/B comparisons between original/remaster, but I try to avoid remasters whenever possible, unless there are an amazing selection of bonus tracks.
Brighten The Corners by Pavement had a 2008 remaster that's loaded with audible digital distortion and clipping, for example. However, the remaster has about 30 bonus tracks, some of which are really good. Still haven't gotten around to hearing the original CD master, from the late 1990s, but I hear it's a lot crisper and more dynamic.
For "unmastered" recordings, anyone heard the story about the "unmastered" version of Death Magnetic by Metallica? Basically, the CD master of that record was extremely loud -- the song I heard was pretty much clipping and digital distortion from start to end -- even the pianissimo parts of the song fill up all the volume range of CD audio. However, it turns out that there was an "unmastered" version with full dynamic range on a Guitar Hero game!