I have a TV tuner for my Macbook that I can play games on, but only SD. If you're looking for HD, you're most likely out of luck. Unless you laptop has a high-bandwidth expansion port, you'll never get the speed you need to play an HD game. USB just won't cut it for 720p or 1080p. But they do make HD TV tuners for expansion ports, so if you've got a decent laptop, an expansion port and a fair bit of money, I'm sure you can find one.
But trust me when I say, you're better off just grabbing a monitor that can handle the console directly. Hell, yesterday Woot had a 22" 1080p for only $100. Much better than trying to fool around with the TV tuner.