That one reunion album the Beatles did in 1981. I mean, I know John wanted to do something in honor of Yoko after that bullet hit her, but John and Paul were just to different by then, and it just reminded us all why they broke up in the first place. But it wasn't a total loss: the stuff George, Ringo, and Eric Clapton put out together after that was amazing!
Yeah! The Trembling Wilburys.. I still love the album they did when they roped-in Steve Winwood...