Easily one of my favorite artists and at this point my favorite guitarist. He was the first artist I listened to where I found myself thinking "you can do that with a guitar?"
My favorite Zappa album is Joe's Garage...probably not a popular pick but it was the first one I listened to and it caters to my love of albums with 3 or more LPs AND my love of concept albums. It's just what rubs me the right way.
His early stuff is great, too. I have copies of the first three Mothers albums and they are awesome! We're Only In It For The Money is a loveable mess of hippie parody.
Still missing a lot of albums I'd like to own, such as Hot Rats, Over-Nite Sensation, Uncle Meat, Shut Up And Play Yer Guitar boxset, and the 'You Can't Do That On Stage Anymore' albums. Sometimes, though, I have nightmares about Frank's humongous discography.