ABC.com has had their foot in the door on web + TV integration for a while. The Who Wants to Be A Millionaire Shockwave game gets so much traffic that that part of the company is practically profitable. I'm just now getting around to trying their Enhanced TV version of the show, a comparable game but synced to the broadcast, so you answer the same questions in the TV game. Finally, you can get points for knowing more than those people. Entertainment value even if you don't like the show--though you have to be watching the broadcast to get the question, which doesn't appear in the web feed.

Good quality sync (at least over my DSL line, though it looks low bandwidth). Each of the four answers for each question has a silly picture that goes along with it, such as maps for geography questions (with a full map after the answer is revealed). Even more impressive is the sponsorship tie-in: during a national TV commercial, you get bonus points for answering a trivia question that requires you pay attention to the commercial. The general strategy to get you to turn on your TV is pretty cool. (See, that's what happens to your priorities when you work for a media site.)