My daughter's favorite is the Cloud b Twilight Constellation Night Light, which she doesn't fall asleep with. She turns it on, grabs her toy space shuttle, and I fly her around her star-lit room on a space odyssey.
I've been having fun with her Trio-blocks gears set, but she can't quite use them herself yet (as I've mentioned before, she's 2.75 and very thin for her age.) She does make requests for me to build.
I have also been impressed by the iPlay build-a-road truck and track set. (Purchased for my 1 year old son to watch.) The trucks are pretty fast, and the track is very easy to put together and modify. It's a flexible track, so any part of it can bend any which way you want.
The Toobeez set is a little harder to put together than I imagined. My children wont be able to successfully make any complicated structures until they are much older... maybe 7? The unexpected difficulty is that the connecting spheres have to be oriented correctly when first inserted for re-connecting to later. If you have it turned the wrong way, you have to re-orient it when it's time to make your third or fourth connection.
