The animales series do start off very childish...ESPECIALLY Clone Wars with Jar Jar's antics, he is eventually phased out and comes back for a couple episodes later on. But do give them the chance, as the series becomes much more interesting with darker themes as the seasons progress. The last season is by far the darkest and is absolutely amazing.
You guys know how Anakin and Obi Wan supposedly had an amazing bond, that Anakin was the best pilot? Yeah, in the Clone Wars you really see this bloom and truly get to see the relationship between these two blossom into what we've been lead to believe from A New Hope and Revenge of the Sith.
Did you know Anakin had a padawan? Ahsoka Tano will become one of your favorites in the series. Her character starts out very childish as well, like the series, but over time she and the series "grow up".
Struggle through the rough patches of Clone Wars, you'll definitely be happy you did. Rebels as well, after about 5 episodes you'll really get into them. Reading A New Dawn may help you get into the Rebels series better, or reading it after watching Rebels season 1 will help you understand the characters background.
I promise you'll come back thanking this thread for forcing yourself to watch the lackluster first episodes of both series.
Walter..