He was a brilliant man, in my opinion. He made some very silly music and hit the radio a few times. He named his kids Moon Unit, Amhet Rodan, and Dweezil. Moon had a radio hit in the 80's (Valey Girl) and Dweezil is a musician too.
Here's my favorite Frank Zappa quote:
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe."
It must be true. He has at least two asteroids named after him. :-)