We bought this as an interim step with a view to getting a Wii in due course, but felt the kids (7 and 4 year olds) were just a wee bit young to spend the money on the Wii just yet (tight, I know!)
Dead easy to set the thing up, graphics are decent enough, and the in-game instructions are dead simple. Controllers are ideal for the wee ones - big and chunky, with motion or joystick settings which is a great option depending on what game you are playing.
The educational aspect of the games is excellent - racing games with "complete-the-word" pit stops and that sort of thing. Ideal.
Best of all - you can store the games in the box, so there's no games cartridges lying about the place.