Tokyo, in my opinion, but I've never been to Dubai and I love Tokyo, so I'm probably biased.
spend one day in and around the actual city itself; do some shopping, sightseeing. For the second day, take a train to Kyoto and spend the day there. Totally amazing and beautiful.
"We are not provided with wisdom, we must discover it for ourselves, after a journey through the wilderness which no one else can take for us, an effort which no one can spare us, for our wisdom is the point of view from which we come at last to regard the world." --M. Proust