1) Heath Ledger (The Dark Knight)
Heath Ledger made Joker his character. In one of the last roles Ledger would ever play before his death, Joker will be the character and the role for which he defined. He’s an anarchist yet sensible. He’s scary yet humorous. The way he intones and speaks as Joker will never ever be something that another actor will master. Heath Ledger is Joker.
2) Jack Nicholson (Batman)
Jack Nicholson made Joker a serious gangster with an infatuation for not just power but art and love or lust. Specifically his love… er… lust, for Vicki Vale. His Joker wasn’t as much for anarchy as Ledger’s, but more planned with a side of jokes in the mix. “Wait ’til they get a load of me.” And with that line Nicholson would hold the top spot until Ledger dethroned him.
3) Jared Leto (Suicide Squad)
Jared Leto’s Joker may just be the closest to Joker in the comics by mentality if not looks. He a high functioning psychopath with a love for Harley Quinn. He also seems like the type that flip a switch between methodical and crazy. I’m looking forward to seeing more of Leto as Joker in movies to come.
4) Cesar Romero (Batman TV Show)
He had the look of Joker if not the demeanor. Of course the Batman TV show was all camp so of the villains, Joker was the most tamed down of the bunch. And don’t forget how Cesar Romero refused to cut his mustache so you can see it through the white paint on his face.
Honorable Mention: Mark Hamill as Joker in the cartoon series and the Arkham video games.
While not a Live action Joker, many will say that Mark Hamill’s treatment of the Joker is the best there has ever been across all media. And he does it with just his voice so while this list is mainly for the Live action films, he deserves a spot even so.