Only the best albums are worth buying more than once. Maybe you lost it, maybe you bought it in different formats—whatever the reason, let us know which albums are worth the investment.
-Rain Dogs by Tom Waits (3 times: it kept getting stolen).
-Band of Gypsies by Jimi Hendrix (3 times: tape, then poorly mastered CD in Japan, then a better master released domestically)
Probably others too, but those are both albums I know I would keep replacing forever if I have to.