I suggest avoiding kiddie tablets and going with a regular tablet with a decent case. It will give the kids/family the best longevity. If they are an Apple family and have tons of apps (kids use parent's phones/touches), then a mini would be great, or an older generation refurbished ipad. I would look to see what the best tablet is vs. the best kiddie tablet.
My 2.5 yo would love any tablet, but has no issue navigating/using the ipad/touch we have. It is freakish how easy they are to use.
Look at the cost of books/apps for the kiddie tablets. That is why I think the Leappad is a rip...the games are $20-$25/each vs. $1-$5 with apple/android.
They will love it! Good luck!