Difficult client, before we asked for more money to cover additional pages they were requesting: "We're really happy with what we've seen so far, keep up the good work" Difficult client, after we asked for more money: "The pages look like toilet paper"…

Not my own experience, but... A coworker was designing a site for a a bunch of jocks who run a sports bar. They continually called to complain that the site wasn't getting done fast enough, and continually ignored my coworker's requests for the content needed to complete it. The client asked why he hadn't inserted the image they'd sent a link to. The link was to an animated gif of a stick figure walking across the screen and peeing.…

Two days after the client handed us the 10th round of changes to their site (a 1" thick stack of printouts, covered in red ink, mostly changing their own copy - again): "I want to know why it's been six months and this site still isn't done!" …

client: "I'm happy to see you've made most of the changes I asked for, but why is there still green on the page?" me (looking at the now entirely red, white and blue page, not an earlier green prototype): "There isn't any green on the page... where do you see green?" client: "The buttons are still green" me (looking at blue buttons): "The buttons look blue on my screen" client: "oh, well it must be because i'm colorblind" …