Your opinion. My opinion (for comic book adaptation) is Justice League & Justice League Unlimited were better than Batman: The Animated Series.
I can make an argument Young Justice is anime and not a cartoon. Otherwise, I would say YJ blows EVERY comic book television series completely out of the water.
to this day...when i re-read my favorite batman graphic novels...batman:year one...long halloween...hush...i hear the voice of Kevin Conroy....and Mark Hamil as the joker.
the animated SuperMan series was also really good.
i remember when clooney's batman movie came out....the animated series released mask of phantasm in theatres.
people were saying it was the better batman movie than kilmer or clooney.
i have all of the batman:animated series on dvd...i cherish them...they were so well done.
especially the writing but the animation....how
dark they made it...was so spot on...and honestly set the tone for nolan's dark knight trilogy.