One time I worked at a company where the idiot who setup my email misread the form where I wrote down my username choice. He though the final d was the number 9 and actually thought I wanted to be dmacdonal9 and then refused to change it afterwards.
My coworkers got great enjoyment from listening to me trying to tell people my email address over the phone, and it became a nickname. But it's nearly never taken when I try to sign up for things, and it is easily remembered.