TFT LCD for PC and TV

We recently purchased a Samsung TFT LCD screen for use with a Sony PC. We also connected the TV signal (via a vcr) directly to the Samsung monitor. This allows tv viewing exclusive of the computer. The picture is good, but could be better.

1) If we input the TV signal directly into the PC (via a TV Tuner Card) and then to the monitor, would we get a better picture (since we presumably would be processing the tv signal digitally)?

2) If the above is possible, which TV Tuner Card woulddo the best job?