At one point in time, I used to collect every CD and CD-single under the sun as relates to melodic rock, hard rock, and heavy metal... but physical and budgetary space dictated some streamlining. So now I focus on just a few specific artists that I go OCD-crazy with, trying to be a completist, obtaining every pressing, international release variant, etc.
This site is my reference when I'm out shopping, so that I have easy access to the data of what is already in my collection (I can't tell you how many times I've inadvertently purchased items I already owned, just because I didn't have that information handy...)
So the list below contains links to individual pages listing the material I have for each artist. I'm always looking for items/pressings I don't already have...