Okay the worst anime I've ever watched? That title goes to an anime I rented one weekend and was the only anime I ever rented where I went "Not only do I want my money back for watching this crapola, I want the hours I wasted watching it back!"
Amazing Nurse Nakano
I'll admit that I enjoy watching a good set of tits bounce, but holy hell Nakao was the only anime I've ever watched where I was cringing watching those things bounce around like floppy torpedoes.
Add to that a disturbing dose of S & M and a plot that a crack addled monkey couldn't even concieve of (I mean we're talking a plot that lurches like Quasimodo here) and we're looking at a POS that I wouldn't watch again if you paid me..