I agree with Buu on the suggestion of Shaman King, currently started watching it and I love! I would have loved more as a child, I reckon.
I however, would have to disagree with one piece only because the majority of the crew members had some traumatic childhood experiences that even got me to tears. I might be a wuss but I'd say a little too extreme for kids.
As a kid, I remember watching stuff like Beyblade, Yugioh, Sakura Card Captors, Sailor Moon, Samurai X, Battle B-Daman, Dectective Conan, Pokemon, Digimon, Monster Rancher, Power Stone, Metabots, Hamtaro and Hello Kitty.