Another memorable moment in TV viewing history was in high school when my friends and I were not even together watching the show. We were watching the Season 3 finale of The OC when a main character died in a car accident. Immediately afterwards, I called a friend and we discussed it for probably longer than we should have. It was a pop culture hit within the high school audiences and everyone was buzzing about it.
It's amazing how groups of people can get so involved in a show that we hold premier parties, quote it daily (maybe not daily), and make audible and emotional reactions to what we see on screen.
If you watch a TV program alone, it does allow you to focus and (at least with girls) there are few chances to have chatter interrupt the viewing process. It is nice to be able to make your own opinions and decide for yourself what you think of situations before everyone gets together. If someone sees something on screen that is displeasing or especially exciting, then those emotions can transfer to the group.
However, watching it in a group is more fun than alone because everyone reacts together, whether it is the same reaction or not. With the common interest, everyone can talk about it later. Its an excuse for everyone to get together (not that we need it) and it opens communication. We all may like the show, but when we watch it together, why each of us likes it is apparent. It is not always for the same reason. One may like a bit of drama added into a comedy while another sees it too depressing. The differences within a common interest come out. People also have different speculations about how the show will turn out, and it is always neat to see the different ideas and to bounce ideas off of others, even though we have no influence on the show's actual outcome.
All of these results from watching a show with a group of people create communication and creative thinking. Therefore, watching these programs with people is just as much of a social thing as it is secluding ourselves from the outside world to watch TV.