There have been other television sitcoms that were similar to Friends but did not leave the same impact. Analyze how this show came to be so memorable and successful. Some ideas would include the diverse group of friends and how people who watch the show also want to have friends similar to those on Friends.
Could be worth comparing what has become character stereotypes with other similar shows too, and how Friends made it work best eg. the loveable womaniser (Joey/Barney in HIMYM/arguably Howard in the Big Bang Theory, even though he fails in his attempts to womanise), the quirky loner (Phoebe/ possibly Robin in HIMYM), as well as other similar tropes which have been adopted from Friends. – Hannah Spencer6 years ago