Television has produced thousands of great shows, but only a handful truly changed the medium forever. These are the series that introduced new storytelling techniques, redefined entire genres, or became cultural events that influenced everything that followed. Even if they are not your usual type of show, they offer something every television fan should experience at least once. Their impact can still be seen in modern series decades later, and many remain just as entertaining today as when they first aired. These landmark shows helped shape television history and continue to inspire audiences, writers, and filmmakers around the world.IMDbThe Twilight Zone (1959–1964)Rod Serling’s groundbreaking anthology proved television could tackle science fiction, horror, and social commentary with equal brilliance.cnx.cmd.push(function() {cnx({playerId: "106e33c0-3911-473c-b599-b1426db57530",}).render("0270c398a82f44f49c23c16122516796");});IMDbI Love Lucy (1951–1957)Its influence on the sitcom format is impossible to overstate, introducing production techniques that are still used today.IMDbThe Sopranos (1999–2007)Widely credited with launching the modern era of prestige television, it forever changed what audiences expected from drama series.IMDbBreaking Bad (2008–2013)Walter White’s transformation remains one of television’s greatest character arcs and set a new standard for serialized storytelling.IMDbThe Wire (2002–2008)Its realistic look at institutions, crime, and politics created one of the most ambitious television dramas ever made.IMDbSeinfeld (1989–1998)The “show about nothing” became one of the most influential comedies ever produced, inspiring countless sitcoms that followed.IMDbMASH* (1972–1983)Blending comedy with powerful wartime drama, it proved sitcoms could handle serious subjects without losing their humor.IMDbThe Simpsons (1989–Present)No animated sitcom has had a greater cultural impact, influencing generations of writers, comedians, and television creators.IMDbTwin Peaks (1990–1991, 2017)David Lynch transformed television with a surreal mystery that inspired decades of prestige dramas.IMDbFriends (1994–2004)Its unforgettable characters and timeless humor turned it into one of the most beloved and rewatched sitcoms ever made.IMDbThe X Files (1993–2018)Its blend of paranormal mysteries and government conspiracies helped redefine science fiction on television.IMDbGame of Thrones (2011–2019)Despite its divisive ending, its scale, production value, and worldwide popularity changed what television could achieve.IMDbThe Office (US) (2005–2013)Its mockumentary style became one of the defining comedy formats of the twenty first century.IMDbCheers (1982–1993)The series perfected the ensemble sitcom, creating characters that audiences happily spent years with.IMDbLost (2004–2010)Its mysteries, fan theories, and serialized storytelling turned weekly television into a global event long before the streaming era.The post 15 Landmark TV Shows Everybody Needs to Watch at Least Once appeared first on Den of Geek.