"The Simpsons:" 23 seasons
"Gunsmoke:" 20 seasons
"Law & Order:" 20 seasons
"Lassie:"17 seasons
"The Adventures of Ozzie & Harriet:" 14 seasons
"Bonanza:"14 seasons
"Knots Landing:"14 seasons
"The Simpsons:" 23 seasons
"Gunsmoke:" 20 seasons
"Law & Order:" 20 seasons
"Lassie:"17 seasons
"The Adventures of Ozzie & Harriet:" 14 seasons
"Bonanza:"14 seasons
"Knots Landing:"14 seasons