I got Young Justice on the mind. I will note that Young Justice is generally beloved by fans and critics alike but there was one fly in the punch bowl, and that is no one really like Young Justice's portrayal of the Joker by voice actor Brent Spiner. I suspect that's why after he debuted in season one they never brought him even though his handiwork is everywhere. Young Justice had a five year time skip between season one and two, and a two year time skip between season two and three. All the Jokers nastiest misdeeds happen off camera. Spoiler: Spoilers Batman fans should know already In the comic books, Joker famously killed the second Robin, Jason Todd. Young Justice inserted this into the first time skip. Joker also famously paralyzed Barbara Gordan/Batgirl leaving her a parapalegic. This happened in the second time skip Mark Hamil probably did the best Joker but it's clear from the wretched abomination that was The Killing Joke movie, Mark Hamil's time is past. Though I give The Killing Joke credit for not having the Joker drink any green milk. Still, the torch must be passed. An honorable mention goes to Kevin Micheal Richardson. The Batman is not as good as Batman, the Animated Series, but it was a reasonable good show and Richardson did a fine job considering he had the restraint of being in a show geared at little kids. The show as a whole was more based on fist fights than detective stories or drama, but it had it's moments. But the most underrated Joker is John DiMaggio (also the voice of Bender the robot and Jake the dog). He played the Joker in the animated movie Batman Under the Red Hood. A very solid film with an all star team of voice actors (Neil Patrick Harris plays Nightwing). I will note that Young Justice tried to make a Joker who was a fusion of Mark Hamill and Heath Ledger. DiMaggio succeeded. As for Harley Quinn. Her character like many characters in the Batman mythos is an exaggerated archtype representing a type of mental condition. In this case hybristophilia. Troy Baker is the voice of the Joker in Justice League Action. In this case, Troy and the series producer clearly want the Joker to be as close to sounding and act like Mark Hamill's joker without actually using Mark Hamill. I bet if you told most people Mark Hamill played that Joker, they would believe you. Still, Justice League Action is clearly geared to a younger audience. The show also plays up the camp more than a bit.