children's tablets for 4y old- any tips?

[eeky]

We are looking for a tablet for our 4y old dd, about to start school in September. No experience of these, just wanted something with lots of educational potential as well as fun things. On Amazon, I can see 2 main tablets - LeapFrog LeapPad Explorer and the VTech InnoTab. Has anyone bought these and what do you think? Or would a Nintendo DS be better (again, clueless regarding gadgets!) We don't have an iPad at home, and I would prefer someting smaller, more robust and cheaper...

The DS seems more of a gaming item imo whereas the Leappad and InnoTab are more educational aswell as fun. There isn't really much between the 2 tbh. I looked into both for a 4yo last Christmas and in the end got the InnoTab as it was cheaper for downloads and was compatible with the KidiZoom camera he already had.

Word of advice tho, either get a charger or use rechargeable batteries as they don't half eat through some battery power! :)