I'm going to go out on a limb and say that it's once, maybe twice, in your lifetime that you will see a theatrical performance like we did with Heath Ledger's take on the Joker. A couple of years ago, with Chris Nolans second installment of the Batman trilogy The Dark Knight, Heath Ledger delivered a performance that was one for the ages.
As a huge Batman fan, I was against Heath playing this character when I first read it online. There was something about the guy that just didn't sit well with me about his ability to play a guy like the Joker. Then I saw the movie and was, of course, blown away. To this day I'm still in awe of Ledger every time I watch his portrayal of the villain who used to scare me to death as a child.
Now, I found this video of singer Tom Waits at the age of 29 in an Aussie talk show. Take a look and pay close attention to the voice, facial expressions, and mannerisms. Heath and Tom worked together on The Imaginarium of Doctor Parnassus...so could this be the inspiration behind the Academy Award winning portrayal of the Joker? Unfortunately, we will never know for sure.
You can skip to the 1:28 mark for the good stuff.