Guiding Light has 57 seasons and 15,762 episodes
http://en.wikipedia.org/wiki/List_of_longest_running_US_television_series
Television shows can last for anywhere from one to ten seasons. It is rare for television shows to have more than ten seasons, even if it is a very popular series. Although, there have been some shows lasting longer than ten seasons. On average shows run for about four to six seasons.
All the seasons of the TV series Bergerac can be purchased on Amazon. Search for "Bergerac tv series" in the search bar to find and purchase all of the seasons.
Most seasons are somewhere between 20 and about 26. It depends on the show.
The television series "MAS*H" aired for a total of 11 seasons from 1972 to 1983. It became one of the most beloved sitcoms of its time, blending humor with serious themes related to war and medicine. The series concluded with a highly-rated finale, which remains one of the most-watched television episodes in history.
There are four seasons in the TV series "Emily of New Moon."
so far 6 are out but there are the new ones from the 7th seasons that play
There are six seasons of the television series LOST which are on DVD.
Looks like there were at least 4 seasons
The TV series "Johnny Test" has six seasons .
House, or House M.D. is a television drama series. Though it has eight total seasons, only the first seven of the eight seasons have been encoded onto a DVD.
The Mission Impossible TV series ran for 7 seasons on CBS, Sept 1966 to March 1973. There was a "revival" run of the show on ABC which started in 1988 and lasted 2 seasons.
The family sitcom television series Step by Step aired a total of 160 episodes in a span of 7 seasons.