Hmm, how high end? I know they're starting to sell HDTV Tuner cards. Very expensive, but obviously a great picture. I have avermedia Studio edition right now. THe TV picture is fairly good as long as you stay away from fast action sequences (ex. watching Penn State play football

) I have yet to mess around with the video input though. But for the 60 bucks or so you get a great remote, all the necessary connections, cable and FM which works well by the way.
Personally I'd stay away from the Hauppage series tuner cards. Granted I don't have any personal experience with them, but the general reviews on them aroiund the net are not very good. It has more to do with compatibility than quality tho, so if it works (in OuTpaTienT's case) then it's decent as well. Also, I wouldn't get sucked in by MSI's new TV@nywhere tuner card. I got one because it looked beautiful for the price... 10bit vs. 8bit and future support of MPEG4 encoding!! All at 60 bucks from Newegg. Unfortunately I learned afterwards that the product has a lot of compatibility issues. A LOT. THe whole package looked as though it was haastily put together and pushed out the door with NILL support.
That's my experience in the tvtuner world.
PSUFan
Oh, and I've also heard the Pinnacle is above average as well. That was the other card I was debating on vs. the Avermedia Studio...