Grand Funk's first two albums undoubtedly shine bright for me, but songs like creepin & the railroad are awesome and make this album pretty great.
This is a jam album that has some really talented artists on it; Mike Bloomfield and Al Kooper of course, and also notable contributions from Steven Stills, Carlos Santana, and Elvin Bishop… the awesome album cover was illustrated by the great Norman Rockwell. There are some great cover jams like The Weight and Green Onions. Super session is often regarded as being better than this release, but this is really great stuff imo.