Elgato's EyeTV is definitely the way to go, not to mention the software that is bundled with it (also developed by Elgato) allows you to pretty much use your Mac as a DVR, as well as encode the content into other formats, like H.264, for example.
I highly recommend it - I've had one for a couple of years and love it!
Check the Marketplace forum, too - someone just had one for sale for $100 that was only a month or two old.
MacDann