Heath Ledger was amazing, but the more appropriate description for his role is FREAKY! I mean it - look at this picture - it says it all. Seriously, I actually had nightmares about The Joker all last night (I felt like I was a little kid again!). I can see why he went out of his mind with insomnia and eventual suicide. It's sad because this is probably his best role ever and he is not alive to reap the praises.
For those of you who saw "Batman Begins" and loved it - you will definitely enjoy this movie. For those who are skeptical - you will be pleasantly surprised. Warning though - it's one for those movies where you need to pay attention and try not to miss small details.