My son loved, loved, LOVED these! We started getting them when he was around 2 1/2 or so, and at almost 6 now, he STILL plays with them every now and then (actually told me the other day he hopes Santa will be able to find Pluto for him, which we were never able to find in stores). The DVD's are great (my son and his older sister both loved them), and best of all, they were free! :) Super-sturdy and a little chunky for smaller hands. One of my son's all-time favorites!! :)
My son is addicted to planet heros! He loves the characters and the DVDs ( you can get them free on their website and some of the planet hero sets come with a DVD ) . I'm amazed how these toys got him interested in space and in no time flat he knew the names of all the planets.