Although some knitters take pride in being able to do so, it is actually inadvisable to knit in front of the TV set. It increases the probability of making a mistake and having to unravel your work later. This is because, when you are seated in front of an enjoyable show, your mind goes in synch with the show and out of synch with your knitting.
I would probably knit in front of a TV set only if I were working a simple stitch, such as stockinette.