Television was originally envisioned as an educational tool, but has become a drug to which Most Americans are addicted. Most of the stuff on the tube is pure crap, with little redeeming value.
Of course there are exceptions.
News, you say? Well, commercial news shows do key you in on some of the latest important breaking news stories, but these stories seem to be selected more for their sensationalism than for their actual importance. And, of course, you have to listen to the stupid commercials.
Movies? Heavily edited, with 20-30% of the footage chopped out to make room for the stupid commercials.
Sports? More stupid commercials. (I do like watching baseball on TV. It's a less violent and more strategic sport than most others, which is why it appeals to me. I mute the commercials, though.)
About the only truly excellent quality TV in the USA is on PBS. "PBS" is the Public Broadcasting Service, a non-profit network of stations across the nation broadcasting high-quality non-fiction and fiction television programs primarily on UHF stations. Three of my favorite PBS series are Nature (about wildlife and natural habitats), Nova (general science), and Mystery (high-quality commercial-free made-for-TV adaptations of classic mystery stories by such authors as Sir Arthur Conan Doyle and Agatha Christie).
As for fiction TV shows on the commercial stations, about the only ones I can stomach are the various Star Trek series (TOS, TNG, Voyager, DS9, etc.). I personally find the Star Trek programs to be the best of the commercial fiction programs. Other similar "spin-off" programs, such as Babble-On Five, are drastically inferior copycats. Two other fiction TV series that I've enjoyed over the years are The X Files and Miami Vice. I'm a science-fiction and fantasy fan. I don't go much for shit-coms -- er, I mean, sit-coms -- because I find them all to be unfunny, stupid, obnoxious, and insulting. And no matter what commercial TV program I watch, I always mute the commercials. Commercials are evil!
So in closing, while there are a few things on TV worth watching, for the most part, television is a vast wasteland full of garbage. I'd rather read a book or surf the Internet. I'm more likely to learn something from that than from watching a typical American television program.