I'm a big Zappa fan (actually saw the Roxy band in 1974 - eat your heart out).  Anyway, in my humble but all important and all knowing opinion, The Grand Wazoo (with its glorious 21 piece jazz orchestra) and Waka Jawaka simply represent the best of Zappa's material from the 70s. Ok, we can throw Roxy and Elsewhere and Bongo Fury in there as well.  Sure, Zappa had bands that sounded this good, most notably the Make A Jazz Noise Here band - but for some reason, this music just sounds more organic than that final touring band (which he regarded as his best band ever).  There are 5 tracks on Grand Wazoo and they are all great.  I have a  particular fondness for the title track and the closing track, Blessed Relief.  If you want to hear Zappa at his very best, you want The Grand Wazoo and Waka Jawaka.  'Nuff said.