We have the Snap Circuits 300, I think. We have 2 of their accessory kits. We also have assorted breadboards, resistors, capacitors etc because we have a few electronic hobbyists at home! The SnapCircuits set gets used off and on, and it was easy for DS to build all the circuits in their sample booklet by himself at age 5.
Snapcircuits have become my DS's "signature gift" for birthday parties for the past few years.
The thing that I wan to add is that please make a strict rule in your house for your kids to wash their hands thoroughly after using snapcircuits. This is not an alarmist warning - I just have this warning in place in my home for all electronic components because they inherently contain metals and chemicals that we might not want our kids to touch (for e.g. the leadfree solder we bought for a hobby project actually contained 25% lead when I read the small print ... etc).
