For me, it's quite good. I don't want to buy a complete set of TV, just to place it on my office. Therefore, TV tuner is a good choice for me. First thing first, if you want to buy TV tuner, consider where you will use it. Picking between internal or external antenna is quite difficult as well.
HINT: Internal TV tuner can be used to capture TV programs ,and store it on your HDD. Pretty neat indeed.
And oh, TV Tuner price is around $120 or so. Shop around for possible lowest price you can find.