I am trying to get his entire catalog. As you can imagine, it isn't that easy. However, these two releases Waterbed (1975) and Surprises (1976) go quite a ways to helping.
I don't think these are his best releases (arranged with that "70s" sound - which makes them seem...dated) - but they do have their moments. "Waterbed," IMHO is the weaker of the two. The title track is one of my favorites, as well as Comin' Home Baby, Deus Xango and Body oil. Bang! Bang! is a decent rendition - but to be honest, I think David Sanborn's version is better.
Surprises also has that "70s sound" but is the stronger of the releases here. Cajun Moon, Asa Branea, The Sound Of Windwood, The Butterfly In A Stone Garden and Anata are my favorites off this release.
I highly recommend these releases for any fan of Herbie Mann. Even though, as stated above, I don;t think these are his best releases, the music is strong as is the production and of course, the music is tight!
Enjoy!