12. Unfinished Business (with R. Kelly) (2004): Another post-retirement collaborative curio. The original Best Of Both Worlds wasn't the huge success that its two makers wanted, so they tried it again a few years later. This time, though, the finished product made even less of a ripple, yielding no hits and leading to a co-headlining tour that ended when one of Jay's associates allegedly maced Kelly. Not that much of a surprise, since most of the second album was leftovers from the first. But the album itself is a bit of one-dimensional fun that's aged pretty well, all Knight Rider keyboard-blips and slithery Kelly choruses. Jay is in imperious-player mode throughout, and he seems to be having fun. But Kelly, who spends a lot of his time rapping in a pinched Slick Rick cadence, effectively walks away with this thing.