Sad but true as it happened to me a few years ago. A friend who had patience searching out the original titles brought some to A/B with my re-issues. We compared RCA's Belafonte Live at Carnegie Hall and Mancini's Hatari. Starting that time, I was convinced a lot of originals out there sounded more natural, although the caveat is to be patient in hunting for a NM copy of the originals. As the QRP Cat Stevens Tea for the Tillerman has taken a beating in another thread, I cling on dearly to my original Pink Island UK pressing.
I have yet to sort through all my old copies of Harry at the Hall. I must have a dozen, picked up here and there at record stores back in the pre-Internet days, all of them cheaply. I should sit down someday and listen through each of them, and note which ones sound good. The ones I do remember listening to back in the day were all pretty noisy, but that may be part of the old RCA 'magic.'
I'm with you on the Tea thing. I have: UHQR, bought new when it came out, various reissues, a UK pink rim and a UK pink label with the litle white 'i.' Fact is, I got tired of the record because it got so overplayed at one point. Ditto on Look of Love- I don't know how many copies of that one i have either, betting at least 6 or 8. (At least with Look, that 45 rpm reissue works pretty nicely when I'm in the mood for it- that's another one that I had to quit listening to for a while because it got so overplayed back in the day).
I've been trying to find old copies of 60's-70's pop on normal pressings that sound good- mostly e-bay cheapies, where I can take the risk for low dollars. So far, I've found great sounding copies of B,S & T's second album, Chicago II (at least one side sounds fab), the old Janis Ian 'Between the Lines.' For kicks, I fired up a really old WB copy of Moondance the other day- I think it was the one I bought when it came out- I was surprised -it sounded better than I thought it would.
I also have at least dozen copies of RL Jones first album, from the MFSL reissue way back when, to a variety of different pressings from different countries. Ditto on multiples of 'Girl at her Volcano' which is an EP i really like- but as far as I remember, almost all of those are a little noisy (though that record can really come alive).
I really should not only to organize my records, but go through the various pressings and sort them sonically. That's work, and I don't think I could stand listening to, say, Dark Side of the Moon 10 times in a row, to determine which one sounds best. Despite my lament, I do appreciate forum postings that identify sonically good copies where it is possible to identify them by country of origin, stamper number, etc.
I probably bought most of the old HP list back in the day, but I can't say i have the best pressings of some of the Mercurys and RCAs. Ditto on the Lyrita's, the Bluebacks, various Deccas, London FFrs, etc.
And when I do go hunting in the stacks, I can never find the thing I'm looking for!