Miles Davis - The CBS Years 1955 - 1985: Blues (CBS, 1988 Box Set)
This is a really good sounding set, with some really nice artwork and a lengthy, well-designed booklet. BUT each LP is organised by a theme (electric, mood, blues, etc) which is in non-chronological order. Even if each track from this theme was in the order of release it would have made sense, but instead it's shuffled together so there's no progression to be heard. Still, it's really affordable and the individual tracks are great.
