Depending on what you use, cable, satellite, or off air, the best choices are different.
Sat is a no brainer, go to CC and get the TIVO box for directtv that like $99.
For off the air, you need a HDTV receiver, and there are some specific cards that work OK.
For cable due to the digital crap your choices are limited, since everything HD is going through their boxes. The service I get, TimeWarner in Socal, has 3 flavors of signal coming to my house, the first 99 channels in analog that my vcr and AIW Radeon can tune directly, so called digital cable which includes all the 99 analog channels plus a mix of a couple hundred more digital channels plus the premium movie channels and all that must go through the cable box and comes out Svhs, AV, and channel 3 which goes into the AIW, but changing channels is so far manual, finally the HDTV is just a different model of digital cable box (that I haven't decided is worth $6.95 a month more to me) with typical HDTV outputs, which I don't think my old Radeon AIW will accept anyway.
Having used the Radeon AIW, my advice would be to buy the $42 (currently $47, but on sale frequently)
http://www.newegg.com/app/viewProduct.asp?description=14-122-132&depa=1 card at newegg.