I'll always have fond memories of Disneyworld, but the answer to the question is Vegas baby! I did only spend a short time there, so I don't know if I could put up with it all the time.
But there is another place which has the complete opposite atmosphere of Vegas. I stayed in a small villa just outside a tiny village, which was itself outside a slightly larger town outside of Rome. It was so peaceful and beautiful and inspiring it was just amazing.