My 7 year old DS loves Steve Spangler - the "Sick Science" kits, the videos, the books, etc. http://www.stevespanglerscience.com

Some of the Steve Spangler kits are available in stores or on amazon.

We have been through most of the other kits available, and just signed up for the Steve Spangler monthly science club kits. Hoping those are good!

He is also a big fan of Home Training Tools.

Also check out "little bits" if your son loves snap circuits.