I bought a Win-TV USB (which included the radio tuner) from Hauppage about 2 years ago, and I've been very happy with it. You can adjust the size of the television window and move it around the screen so that you can do other stuff on your machine. It was very easy to set up.
I only had one problem with it, and that was when I upgraded the software for it. The quality actually went way down. I got a streak across the top of the picture, and I couldn't change channels when the window was maximized anymore. I ended up reinstalling the old software and that fixed the problem.
Overall, I'd recommend it.