I am looking for a card that will accept cable televison, has a good picture at a larger screen and 5.1 surround sound.
*cable television: If its analog non-premium channels below 125, most analog tuners will work and tune the channels, if its digital cable, satellite or premium analog that requires a decoder box (STB) then most analog tuners will work, but the decoder box will have to tune the channels and input via composite(rca), s-video or coax with the tuner tuned to channel 3/4. There are no PC tuner cards that tune digital cable.
*Good picture at larger screen: The tuner itself is a small contributer to Picture Quality. The analog/digital converters(ADC) contribute a little (12bit is better than 10bit which is better than 8bit), but signal strentgth, software and grahics card probably have the biggest impact on Picture Quality. An 8bit tuner with dscaler can have pretty good PQ, while a 12bit tuner with software conflicts may not work at all. At best NTSC broadcast TV is only 'OK' anyway.
*5.1 Sound: Analog TV broadcasts are Mono or Stereo, no 5.1.