'Dr. Kawashima's Brain Training: How Old Is Your Brain?'
Essential skill: How to be smart
Format: DS
The dear doctor must be raking in the cash as his brain training exercises can be done by everybody from young children to grand parents across the globe.
There are two titles available on the DS, both of which offer an array of mind-boggling exercises which when completed will then generate a theoretical brain age based on your responses. The younger your brain age the better.