Hands down mine is Dark Side of the Moon. I still play it several times a year from start to finish. I remember as a kid 40+ years ago recording DSOTM on our station's "midnight theatre" on my R2R deck and wearing it out. I eventually got the album and found als MFSL version at a garage sale. I owned a few US LP versions before Cd's came on the scene. Probably the most versions I have purchased of any album (Vinyl, tape, cds, sacd).