The Dark Knight Joker
Over the years we have seen some brilliant portrayals of the Clown Prince of crime and for if you take Jared Leto's performance from the Suicide squad I think we could say everyone joker to grace the big screen could have been a 10 out of 10.
A personal favorite is the Heath ledger joker from the Dark Kight, his version of the joker felt more human and he believed in chaos, he simply wanted to watch the city burn.
There are little in terms of an origin story, he was introduced with just his calling card "A Joker Playing Card", we didn't get a match from the joker about where he came from, throughout the movie he explained how he got his scars but every time it was a different story.
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He wanted to convince the city that he could turn a Hero into Villan and that's how Two-face was born, he turned Harvey Dent against the city.
It was sad that Heath Ledger passed away, He really gave life to the comic book genre in a time where there wasn't much focus around it.