A recent study by the University of Maryland compares the activities of happy and unhappy people. No real surprises here. Happy people are more social, go to church more often, and read more newspapers. Happy people also watch TV, but they watch less than unhappy people.
The question still remains whether or not unhappy people tend to watch more TV or whether watching more TV is what makes you unhappy. Also, because unemployed people watch more TV, it's possible that unemployment contributes to the unhappiness.
According to a NYTimes.com article featuring the study's author John Robinson, "We looked at 8 to 10 activities that happy people engage in, and for each one, the people who did the activities more--visitng others, going to church, all those things--were more happy. TV was the one activity that showed a negative relationship. Unhappy people did it more, and happy people did it less."