I have a signed Ian McCulloch Mysterio I wouldn't part with even though it's a fairly crap album. I've some RCA Bowie discs which would cost a fortune (I imagine) to replace off eBay. I have some British bands (Amusement Parks/yourcodenname...) which don't find themselves on American record store shelves very often. These are not necessarily my favorites, but they are the first discs I'd grab in case of a fire.
In this sense,
Your Most 'Valuable' CDs!