There was just an ad on TV for one of those evil gambly "auction" sites (the ones where you pay to bid rather than paying for the item), and one of their example things was a car that "sold" for about $500 on a $35000 car. And it struck me, when you buy a thing at a discount, the difference doesn't count as income for tax purposes (unless maybe you're a business). But when Oprah gave people cars, they got screwed with a huge tax bill and it caused all sorts of silly problems.
Perhaps you've already spotted where I'm going with this - when a TV show is giving out prizes, perhaps instead of contestants winning a car, they should just win the option to purchase a car for 1 cent. Logically the buyer in this transaction can't be taxed without also attempting to tax every customer every time a supermarket has a discount on cereal, every time someone buys a new car without paying full sticker price (ie. every time someone buys a new car at all)... basically, any time anything is discounted from "full price" in any way. It would be ridiculous to try to enforce that. (I'm sure the US government is that ridiculous though.)