Ok, just few quick hidden gems you should definitely pick up:

1. Super Sessions w/ Mike Bloomfield, Al Kooper, and Steven Stills. This CD is amazing and has great repeat playability.
2. Hot Tuna [live] It's actually the one that comes up first when you search on Amazon. It's got a blue and red cover. Some great acoustic blues. The guitar playing is exceptional.
3. Pinetop Perkins Any album. I don't really know which album to suggest, I just have a bunch of mp3's. But its some of the best blues piano playing I've ever been able to find. Mostly of the early Chicago blues variety.

That's about all I can think of right now that hasn't already been mentioned. Enjoy!

-Josh