Before the mid 2004 I did not consider sitcoms as being something worth watching. I was thinking that it is impossible to keep up something funny and smart for 100+ series. In 2005 I first got a DVD from friend with some series of Friends sitcom. Surprisingly to myself I found them quite entertaining and I ended up watching all 10 seasons little by little. These days I do believe that [even] sitcoms can benefit people and they are not just make you a couch potato.
One of the things that you start picking up is the language with all the idioms, expressions and, of course, jokes. Second, I tend to believe that sitcoms teach people about the relationships, even though the script writers take it a bit too extreme from time to time. In addition to that it can help one to laugh and relax after a hard day at work.
I do not like every sitcom but I do like some. And some are taking longer time to get the idea what makes them special (like Simpsons, for example).
When I came to Sweden, I picked up 2 more sitcoms that I started watching. The first one was Two and a Half Men and the second was Scrubs and I think both are pretty good (even though I think of two, Two and a Half Men is a bit better produced). So, I do find it fascinating that the writers continuously find strengths to come up with more stories and jokes and ways to screw up relationships and, most of the time, put them back together. Or is it just me missing the English language?