Which cartoons do your kids love?
We don't have them on *too* often (especially during summer), but when my daughter needs some down time, she likes Bubble Guppies and the Wiggles. She used to love Yo Gabba Gabba - I'm so glad she's out of that stage!!
My wish was that she'd like the Disney stuff...but so far, no. Putting on a Disney movie is a guarantee that she'll leave the room to find something else to get into.