This small central Florida city is without a doubt the world's theme-park capital. In and around Orlando there are as many as 15 parks for a variety of ages and tastes - and if you rent a car, in a week you could manage to visit nearly half of them (including if you're a driver under 21).
In order to make this work, you of course need to decide in advance which parks you want to visit (and in some cases also reserve ahead). The main half dozen or so are of course the ones operated by Disney World and Universal Studios, but they're far from the only game in town. Here's a rundown of five which I think are especially worth at least a day of your vacation time.