I suppose it depends on what you are going to watch. A political discussion between opponents is a quite different thing that a soap opera. Also, it's not just a question of words but more a questing of practicing the language and, for example, sitcoms use a rather basic vocabulary but the actors speak fast and use colloquial expressions. So, since there cannot be a tangible answer to your question, just keep on learning and practicing and focus in making progress. And good things will come eventually. :)

Hi Sakra, There is not absolute recipe for this specific question, nevertheless I certainly believe that you must be aware of the phrase "Practice makes perfection"! If you wish to listen to a daily television shows, it is not required to possess a highly cultivated knowledge, however if you wish to listen to political debates, then you need to be highly familiar with the language. Hope this answer has clarified your concerns