Sometimes a really good interactive is a very simple one.
I love this horse because it is life sized, realistic, in a quaintly themed area with a really good opportunity to fall off and hurt yourself. My instincts would be to surround this thing with fencing and padding and to have it staffed with eight team members and a mop made of band-aids.
You'll find this horse at the Discovery Gateway Children's Museum in Salt Lake City, Utah.
Damn I've got a Big Head.