Positive -
1) discover and learn about new things : sports, cooking: economy: medicine, history, architecture (interior design, how to make things),
2) there are the classical books made into films - Dickens, Jane Austen
3) You can watch sports matches that you may not be able to go to - World Cup
4).  There are also lots of different series - comedies, thrillers, historical, suspense
5) You can also listen to music and learn some dance moves.
6. Watch the news all the time

However, the TV is not all great.
1. You can not turn it off and forget about homework, doing your chores, going to bed
2. Watch a show that has a negative effect on you - go jump off a roof into a swimming pool
3. Some people use the TV as a babysitter.
4. Some people can become depressed when they watch too much TV
5. Some reality shows are very dangerous because people think they can try out the tricks on their own