I hope there's not another Joker in the Nolan franchise. I'd be fine with a different take on the character in a different Batman film, but it'd suck to have someone imitating Heath's performance. I doubt Nolan would want that either.
Johnny Depp, James Franco, Daniel Day Lewis, or Joseph Gordon Levitt. However, if Nolan did change his mind and decide to recast, he'd likely go with someone unexpected as with Ledger and not any of the popular choices, which I wouldn't mind. I trust in Nolan.
I dont see anyone imitating him either. I think Joker could be a mastermind behind some evil plan even though he's in jail. In that case they wont even need to show him. Just some guy sitting in his cell in shadows. Imitating Ledger's voice is better than imitating his performance.
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Azula: My mommy didn't love me so I'm going to burn down your village.
That'd be a stupid move. When people want the Joker, they want to see him. If it's going to be a cameo or just a guy in the shadows, there's no point. Besides that, it's been shown that almost nothing is consistent with the Joker's personality, so the actor wouldn't even have to imitate Heath's performance, and would be free to bring something new to the table.
Im not saying that a guy in the shadows should be the only villain of the movie. There should be someone else, like Riddler, a new story etc etc Joker could just appear at the end of the story to remind Batman that he's not gone. He could be behind the story somehow.
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Azula: My mommy didn't love me so I'm going to burn down your village.
I know that's not what you're saying but the Joker is too much of a visually appealing villain to only be behind the scenes for every new movie coming out.
What? Even if he doesn't appear again in this franchise he'll be in the next. It's not as if we'll never see the character again. Besides, Batman has a ton of other awesome villains to be used if the Joker doesn't return.
Exactly, like:
The Penguin-not the main villain, just a mob boss who hires a few goons, or as someone suggested before, be Batman's insider to the mob scene.
The Riddler-Hired to find out Batman's true identity. Forces Batman to solve some puzzles that are meant to entrap him in some way.
Talia Al Ghul-If she were to appear, she'd be running the show with a few hired assassins working for her.
Firefly-Either a hired hand, or working alone, he would be interesting but probably not the main villain
Poison Ivy-A bio-terrorist
Mad Hatter-filling in the possible gap of insanity left behind with no Joker. No mind control hats, though. Just hats that serve other mechanical functions.
The Reaper-We've already seen Batman clones who carried guns and were ready to kill, so would it be too far a stretch to see one of them become a completely unique vigilante?
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I love Brandon Lee, and thought he was just awesome, but I doubt he'd be able to fill Heath's shoes. Also, Daniel Day Lewis isn't the only person who'd be able to pull off a great performance with the Joker. Think of Johnny Depp, or James Franco, who are both versatile actors.