Comment Humble Bundle (Score 2) 338
Some of the humble bundle titles (chocolate castle, crayon phisics) are pretty good and educational, stimulating the brain. A three year old is a bit too young, but I would suggest you play together -- this way you can help the child, strengthen the bond between the two of you and steer the educational and entertainment process.
However, please keep in mind that there was an article a few weeks ago that exposure to TV (and maybe a computer?) at an early age may hamper a child's cognitive development.
Why not crack open a good printed book with nice illustrations and read to your child? Or play some old fashioned games. Or kick ball, learn to ride a bike, etc etc. You'll be thankful one day that you did. And your child will, too.