Which city would you recommend for a week-long visit?

The 3 cities that are currently high on my wishlist are Tokyo, Bangkok and Hong Kong. All three are on the same continent, which is preferable to me. But which one of them is the most interesting and rewarding for a week-long visit? I've never been to any of the three before, so it will be my first visit!<br><br>What factors should I take into consideration when deciding?