Do your kids like Batman the Animated Series?
Batman the Animated Series is said to be the greatest superhero cartoon of all time. and films like The Dark Knight are NO WAY suitable for kids but Batman the Animated series is near perfect as it's nice and dark but not to dark and the animation is AMAZING and it's made using traditional cell animation (I think) and The Joker is voiced by Mark Hamil
It also uses music from the 1989 live action batman movie and the cartoon came out the exact same year I was born. definitely a cartoon lots of kids will like.
Unfortunately as it's quite old now (1992) it'ds not on TV anymore so you might have to buy the DVD
and the newer Batman cartoon series are no where near as good
There still good though but more childish. By the way KIDS ARE AWESOME