A successful television show has three things: an interesting premise, a talented cast with great chemistry and a complete storyline. Many of the most beloved shows and sitcoms of all time have followed this formula exactly, delivering a great product for many seasons until ultimately ending after running its course. However, certain shows don't seem to know when to quit, and Grey's Anatomy is at the top of the list.

Currently in its eighteenth season, Grey's Anatomy first aired in 2005 and is the longest-running scripted primetime show currently on the air on ABC. The medical drama starring Ellen Pompeo and helmed by Shonda Rhimes was an instant hit with fans and critics, providing a perfect mix of medical drama and sex appeal that viewers couldn't get enough of. Younger and edgier than most medical soap dramas, Grey's took network television by storm and continues to do so.

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A Grey's Anatomy promotional image showing a group of doctors in a hospital ward

However, the most recent seasons have shown a steady decline in both viewership and ratings. Could it be possible that the very drama that kept fans coming back for more is now too much? There are a few reasons why Grey's is losing steam, with the star and executive producer Pompeo even saying she's ready for the show to end. Here's why it's time to say goodbye to Grey's Anatomy.

Grey's follows young medical interns, attendings and residents as they begin working at Seattle Grace Hospital. While working so closely with each other at all hours of the day, both intimate and platonic relationships form amongst the doctors, often throwing an emotional wrench into the real-life medical drama they often face daily. While not the longest-running show on television by any stretch, Grey's has gone through its fair share of plot points. At this point, the original storylines from earlier seasons are so much more grounded in reality than current seasons that it almost feels like two different shows.

Fans have seen it all -- literally -- throughout the show. While the early seasons were filled with high-stakes medical emergencies, they were still realistic enough for fans to easily follow. However, as the show has progressed, the plots of each episode have gotten bigger and bigger, thrusting the doctors into the throes of multiple plane crashes, a hospital shooting, residents sleeping with each other (and in some cases, patients) and more. The truth of the matter is that viewers have never really watched Grey's for medical knowledge anyway; it's all about the characters and their relationships.

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Grey's Anatomy established actors like Patrick Dempsey, literally monikered McDreamy by fans after his turn as neurosurgeon Derek Shepherd, and gave Sandra Oh the chance to truly shine in one of fans' favorite roles, Dr. Cristina Yang. From the first season, Oh received Emmy nominations for Outstanding Supporting Actress in a series every year until 2009. While both were considered cast staples on Grey's, both Dempsey and Oh, like many other cast members, ultimately made their exit from the medical drama, which seemed to be the catalyst for the low viewership and ratings seen in recent years. Grey's just can't seem to capture the same energy and sparkle that it had with its initial cast.

At times, even die-hard fans of Grey's Anatomy feel that the show has overstayed its welcome. With too many newer characters, old characters dying and/or returning from the grave in mysterious ways, confusing subplots and over-the-top drama, Grey's is beginning to feel more and more like a parody of what it once was, and it seems that the showrunners now have a runaway giant of a show with no real way to end yet. Fans, critics and even executive producers have expressed their desire to end Grey's Anatomy, but with no concrete finale in sight, there's no telling when that might be.

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