1. Fiona Apple, Extraordinary Machine
After famously rejecting a version recorded with Jon Brion, her label finally put out a rejiggered one produced with Mike Elizondo in 2005.
2. Beach Boys, Smile
A post-Pet Sounds concept album with nearly as many different versions as it had delays, including two official discs released in the past decade.
3. David Bowie, Toy
A 2001 set focused mostly on his early work was aborted. Some songs ended up on Heathen; others recently leaked.
4. Zach de la Rocha, Untitled album
The Rage Against the Machine frontman reportedly recorded with Questlove, Trent Reznor, DJ Shadow, and Tom Morello, but only one song ever surfaced.
5. Green Day, Cigarettes and Valentines
When the master tapes were stolen in 2003, the group decided to start from scratch yielding the 2004 blockbuster American Idiot.
6. Prince, Dream Factory
This double album recorded after Purple Rain might be the most intriguing of countless scrapped Prince projects.
7. Weezer, Songs From the Black Hole
Black hole indeed. This space-themed rock opera remains unfinished, though tracks leaked in 2002.
8. The Who, Lifehouse
The band abandoned its rock-opera follow-up to Tommy for 1971's now-classic Who's Next; some songs did appear on later albums.