Try the food at Knott's sometime--really, really inedible! Bleaaahhh!! At least it's not that bad.
I am most grossed out by the reconstituted "chicken" strips at Paradise Pier, at the Malibu Dips and Strips or whatever it's called. The "chick'n" looked like cottage cheese or something.
Worst indigestion award goes to Rancho del Zocalo.
One time I got a salad from Pizza Port and it had some kind of larvae thing wriggling around in it. The manager came over, looked at me totally deadpan and said, "What? You didn't want larvae on your salad?" I had to admit she was pretty funny, and that was some slick guest handling on her part. They gave me a refund, etc.