Man...you had to bring up William Hung. I hadn't thought about him for years and now I read his name and his awful voice comes flying into my head. I'd rather hear someone scratching a chalkboard than listen to him.
There have been quite a few on through the years that just made me want to shut the television down then and there...lol. I guess I'd have to agree with Hung being one of the absolute worst, however. Poor guy was lied to all those years that his friends told him he could sing.