The Numero label's "Eccentric Soul" series of comps had some good stuff, lots of regional and small label 60s & 70s soul/r&B. I'm a fan of the "ABCs of Kid Soul" installment, which is all kid groups and Jackson 5 knockoffs. Another compilation series I enjoy is the (now out of print?) "Dream Babes", which focused on female singers and girl groups of the 50s & 60s.
Also, if you look through the old playlists for Cherry Blossom Clinic and Evan Funk Davies they often pull from some good comps - I think that's how I first found out about some of the recent glam reissue compilations, like "Glitterbest", "Velvet Tinmine", etc.
And of course I have to plug "CD86".