Talk about your worst clients (no names please!)

One of my worst was a guy that emailed me saying he'd found a typo in his copy. Not a big deal, right? Well, the guy insisted on saying such things as "you clearly wrote this without any second thought" and "this isn't the kind of quality Corey Freeman can produce." Needless to say, I don't work with him anymore. Never trade money for disrespect, not that he ever kept track of his payments.