This two-CD, 51-song set covers virtually everything the group recorded with Steve Winwood in the lineup from 1964-1967. The gap between the band's best and worst material was considerable; quite a few of their R&B covers are surprisingly routine, and the occasional cuts that don't have Winwood on lead vocals are downright pedestrian. Because of this inconsistency, the general fan's better off with the Rhino best-of, if it can be found. If you want to get more, though, this is the first and last place to go, with all the hit singles, everything from their three albums, an early EP, some B-sides, and a couple of previously unissued tracks. And some of the obscure material is really good, whether in a straight R&B/blues or more soulful vein. Be aware that the version of "Gimme Some Lovin'" here is the less dynamic, original British mix, minus some backup vocals and percussion.