Around 67? I think Jefferson Airplanes, Flying Burrito Brothers...
Zep were fantastic. I destroyed couple of LP's from listening too much to them:)
Shifting to the progressive stuff,there was also Procol Harum :) I saw them in concert 2 years ago and they can still rock.

How about Deep Purple? I really prefer their early stuff , before Gillan , with Rod Evans( DP I & II, Books of Taleysien).