Tim Curry famously voiced the Joker on Batman: The Animated Series before being replaced by Mark Hamill - here's the only known audio of his performance. Batman: The Animated Series debuted in 1992 and while it was a kid's show it still took Batman and the material seriously. It tackled some dark theme and topics and its many achievements include the complete reinvention of Mr. Freeze with the season 1 episode "Heart Of Ice."
The show also cast Star Wars' Mark Hamill as Batman's most famous nemesis the Joker. This left many bemused until they saw his performance, which is now acclaimed as one of the best interpretations of the character. Hamill was also following in the footsteps of Jack Nicholson's famous portrayal from the 1989 Tim Burton Batman movie. Hamill has routinely returned to the role over the years, including video game Batman: Arkham Knight and animated movie Batman: The Killing Joke.
Before Mark Hamill was cast, Tim Curry was hired to play the Joker on Batman: The Animated Series. Curry was actually one of the contenders for the role in Tim Burton's movie, alongside Robin Williams and Willem Dafoe (Aquaman). From the outside, Curry felt like perfect casting, especially coming off the back of his acclaimed turn as Pennywise the Dancing Clown in the 1990 IT miniseries. The actor reportedly recorded four episodes before being replaced. There are conflicting reports over why Curry exited, with the actor stating he had bronchitis at the time and the part was too much of a strain on his voice, while the showrunners apparently didn't think his take was working.
Regardless, Mark Hamill quickly came onboard and the rest is history. Sadly, none of the Tim Curry Joker audio for Batman: The Animated Series has ever been released, and while fans would love to hear it it's likely to remain locked away. That said, a tiny piece of his Joker work remained on the show itself. During season 1 episode 9 "Be A Clown," a young boy named Jordan is fleeing from the Joker and runs into a Robot Clown, which starts laughing. This vocal performance is from Curry and was based on the Joker laugh he was using during his recording sessions.
It appears Curry had no ill feelings about being replaced on Batman: The Animated Series, as he later voiced a role in the episode "Fear of Victory" and the Batman Beyond episode "Final Cut." He no doubt would have made for a great Joker, but if he had stayed with the show, the world may have missed out on the gift of Mark Hamill in the role.