Essential Zappa: what's missing from my collectio

I'm more interested in the instrumental side of Frank / Mothers. This is what I have so far:

The Yellow Shark: Personally, I think this is far and away
the best thing he ever did.
Waka Jawaka
Apostrophe / Overnight sensation
Civilization Phase 3
Hot Rats
Essential Zappa
Classical Zappa
Orchestral Favorites
Studio Tan
Freak Out

It turns out I had more than I thought. Looking to fill in the holes in my collection. I took out "Lather" from the local library and thought it was ok. What about Chunga's Revenge (SP?)and Mothers Live (think it was a live concert recording from Austin, Tx.)?
BONGO FURY & Zoot Allures ! if you like Zappa you must have them all ! I have around 70 Zappa cds
Belief that there is one best FZ release requires defective playback equipment or more likely egregious user/listener error. A lot of his ideas mutate and resurface throughout the catalog. Uncle Meat, Lumpy Gravy and Weasels Ripped My Flesh lay down a fair chunk of early compositional foundation. Hot Rats, Waka Jawaka (Hot Rats II) and Grand Wazoo are also superb. The good poop doesn't stop here though. Overnight Sensation, Apostrophe, Roxy and Elswhere, One Size Fits All, Zoot Allures and the Joe's Garage stuff all have some amazing parts on em'. Trying to sum up Zappa's output is not a small task, but compositions like Twenty Small Cigars, Peaches en Regalia, The Black Page, Echidna's Arf, King Kong, Zoot Allures, Sofa, Easter in Watermelon Hay, The Little House I Used To Live In and Inca Roads will probably stick around for quite awhile.
'Weasels Rip My Flesh' & 'Live At The Fillmore', both Mothers albums, were released around the 'Hot Rats' & 'Chungas Revenge' period, and while not being totally instrumental (although there are some amazing instrumental cuts on both!), they totally fit in the sound amd mindset of FZ at that point in time. He was on fire at this point of his career! These records are must-haves for any FZ fan.