Another vote here for Elgato and EyeTV.
Elgato makes a range of EyeTV hardware suitable for receiving analogue terrestrial, digital terrestrial, satellite and cable televisions.
Some of their models will also accept an input from (say) a VHS video recorder or a games console, allowing you to capture content from those sources too - but there are other ways of doing this too.
Go to their website and pick the one for you.
All Elgato hardware comes bundled with the EyeTV 2 software, which absolutely rocks. From there you can export to iTunes for viewing on an iPod or

TV. Don't settle for anything else.
If you also get Toast 8 Titanium, you can burn your recordings to DVD.
SL