Grey’s Anatomy had plenty of impactful episodes, but some were so groundbreaking that they changed the show forever. The show first started in 2005 and has since aired hundreds of episodes, with Grey’s Anatomy season 20 marking an incredible 19 years since its beginning. The best episodes of Grey’s Anatomy influenced the show’s overall lore and characters, and some were so bold that the after-effects of its storylines continued to be relevant years later.
Throughout the show, Meredith Grey (Ellen Pompeo) and her colleagues dedicated their lives to being medical professionals, but there was plenty of personal drama alongside their careers. Grey’s Anatomy’s best couples provided huge amounts of chaos, for example. There were also several moments in which the characters faced danger and feared not only for their lives but also for the lives of their patients. Despite there being over 400 episodes of Grey’s Anatomy, ten stand out as the most defining installments of the hit medical drama TV show.
10. Who’s Zoomin’ Who?
Season 1, Episode 9
The Grey’s Anatomy season 1 finale, “Who’s Zoomin’ Who?” featured the unexpected return of Addison Montgomery (Kate Walsh), Derek Shepherd’s (Patrick Dempsey) ex-wife. “Who’s Zoomin’ Who?” distracted from her arrival by initially focusing on a syphilis outbreak, and Derek and Meredith’s relationship in Grey’s Anatomy continued to build anticipation. As she felt safe and secure in her new budding romance, Meredith’s world came crashing down when Addison appeared and uttered the iconic line, “You must be the woman who’s been screwing my husband?” to her.
Addison’s abrupt arrival was arguably the biggest plot twist of Grey’s Anatomy season 1. Although Derek mentioned Addison in passing before this, it was still a shock to see the woman walk through the front door of the hospital. It was known that the pair’s marriage fell apart because of her affair, but the tension between Derek and Addison and her first impression of Meredith made the moment even more dramatic. As season finales go, “Who’s Zoomin’ Who?” was an amazing way to wrap up the first installment of the show, and Addison’s presence continued to impact it long afterward.
9. 17 Seconds
Season 2, Episode 25
There were two core reasons as to why the season 2 episode “17 Seconds” impacted the show so much. The first was the Grey’s Anatomy love triangle between Meredith, Derek, and Addison, which saw huge development when paranoia and tension caused several awkward conversations between the three. However, the main reason was Izzie Stevens (Katherine Heigl) getting desperate in her attempts to help Denny Duquette, Jr. (Jeffrey Dean Morgan). Denny’s heart issues resulted in him being treated with an LVAD, but Izzie realized that cutting its wiring would bump her beloved up the transplant list.
When a heart became available, it was initially intended for another patient, so Izzie cut the wire. Izzie knew that his sudden heart failure would make him a priority, which was a little selfish to the other patient. Izzie was deeply in love with Denny by this point in his storyline, so her feelings dictated her actions. However, Denny’s transplant didn’t help him for very long, and shortly after, he died from a clot. Denny and Izzie were soulmates in Grey’s Anatomy, and his heartbreaking death stuck with Izzie throughout the rest of her time in the show.
8. Didn’t We Almost Have It All?
Season 3, Episode 25
“Didn’t We Almost Have It All?” was a massively shocking episode in Grey’s Anatomy for several reasons. It set up two prominent storylines that were heavily featured later on: Richard Webber’s (James Pickens, Jr.) struggling with his wife’s health and George O’Malley’s (T.R. Knight) decision to repeat his internship. However, the most show-changing development was the departure of Burke in Grey’s Anatomy. On his wedding day to Cristina Yang (Sandra Oh), the two attempted to keep their nuptials a secret, and their previously agreed small wedding became an over-the-top affair. At the last moment, Burke suddenly got cold feet.
This was a massive surprise because he’d spent the episode reassuring Cristina and knew her anxieties weren’t anything to do with her feelings for him. What made this moment even worse, however, was that Burke didn’t stick around and face the consequences of his actions. Cristina returned home to find his possessions gone as if he had never been there. Burke’s heartwrenching actions stuck with Cristina long after, including when she got pregnant by Owen Hunt (Kevin McKidd), and the character was permanently scarred by her runaway fiance.
7. Now Or Never
Season 5, Episode 24
“Now or Never” saw the death of a main character in Grey’s Anatomy, but the build-up to it was extremely unexpected and drastically altered the overall tone. George O’Malley’s death demise was rather tragic, mainly because it took so long to identify that he was patient John Doe. After significant character development for George led him to decide to join the U.S. Army as a trauma surgeon, Webber allowed him to take his last day off. However, George was hit by a bus while trying to save a woman’s life and quickly ended up back at the hospital.
Because of severe facial scarring, his colleagues didn’t realize it was George. The only reason he was identified was because he wrote “007” on Meredith’s palm, which was a brilliant callback to some of their earlier episodes and created a sense of continuity and closure. George was the first of the original group of interns in Grey’s Anatomy to die, so this was a horrific moment that traumatized the likes of Webber, Meredith, and Cristina forever.
6. Sanctuary & Death And All His Friends
Season 6, Episodes 23 & 24
The two-part finale episode of season 6, “Sanctuary” and “Death and All His Friends,” marked a petrifying moment for the staff of Seattle Grace Hospital. The hospital’s mass shooting impacted every character in some way, which was demonstrated through multiple action-packed and emotional scenes. Alex Karev (Justin Chambers) was shot, which left Lexie Grey (Chyler Leigh) fighting to keep him alive while also confessing her feelings, for example. The astonishing end of this situation involved Webber standing up against the shooter, who then killed himself.
There were multiple reasons why this two-parter changed Grey’s Anatomy forever. The show tackled a topic that was, unfortunately, a situation that many have experienced. The panic and trauma that everyone experienced was awful, but it was especially hard for Meredith, who miscarried while tending to Owen’s gunshot wound. However, Webber easily came out of the shooting the worst, as the memory of the shooter’s suicide was heavily engrained in his brain.
5. Flight
Season 8, Episode 24
The season 8 episode “Flight” included one of the most astonishing storylines in Grey’s Anatomy history, and the show felt the repercussions of it forever. The Grey’s Anatomy plane crash was impactful to everyone involved, but especially Meredith. Meredith sustained minimal injuries in the crash, but she sadly lost both Mark Sloan (Eric Dane) and her sister Lexie. Mark amazingly managed to survive long enough to say goodbye to Lexie, but in the season 9 premiere episode, it was revealed that his life support had been turned off, and he’d also perished.
Regaining consciousness in the wreckage was terrifying enough for everyone involved, but for the survivors to have to sit and watch two of their closest friends succumb to their injuries was another level. It was a situation that couldn’t be controlled, regardless of their incredible life-saving skills. The episode’s exploration of loss, trauma, and resilience captured the essence of Grey’s Anatomy brilliantly despite being so unexpected. The plane crash was a horrific event, but one that shaped and molded several other storylines and character arcs afterward.
4. Fear (Of The Unknown)
Season 10, Episode 24
Cristina Yang’s departure in Grey’s Anatomy season 10, during the episode “Fear (of the Unknown),” was emotionally charged and poignant. Throughout the episode, Cristina grappled with bidding farewell to those closest to her and the hospital, reflecting on her journey as a person and a medical professional. In between a flurry of incoming victims of a nearby terrorist attack, Cristina proved to herself that she was more than capable of taking on her new job in Zurich. “Fear (of the Unknown)” was full of profound moments for Cristina, especially with Meredith.
“Fear (of the Unknown)” was one of Meredith and Cristina’s best Grey’s Anatomy episodes because of their heartfelt goodbye. Their friendship was a staple of the show, and even after Cristina’s exit, she remained Meredith’s very best friend and most trusted confidant. This episode gave Cristina a well-deserved fresh start, and her tenure in Grey’s Anatomy continued to be referenced throughout. It also introduced another half-sister of Meredith’s, Maggie Pierce (Kelly McCreary), who became a crucial figure in the show.
3. How To Save A Life
Season 11, Episode 21
“How to Save a Life” was one of Grey’s Anatomy’s saddest episodes because of the car crash that led to Derek Shepherd’s agonizing death. One key story arc in season 11 was Derek’s job with the President in Washington, which caused some conflict in his marriage to Meredith. Although Meredith was proud of her husband’s achievements, she was less than happy about his absence from their children and that she was unable to kickstart her own career. Derek decided to quit his job, but on the drive to hand in his resignation, he was fatally wounded in a collision.
Derek proved himself to be a doctor first by helping the injured, which was an appropriate sentiment for the character, but it also caused damage that resulted in his death. Derek was a huge part of Grey’s Anatomy and an integral character from its pilot, so his demise was a significant moment for the show. However, Derek’s death in Grey’s Anatomy also shifted the overall tone of the show and allowed for new storylines. After this, there was a big focus on Meredith coping with the loss of her husband and raising their children alone.
2. My Shot
Season 16, Episode 8
In the season 16 episode “My Shot,” Meredith faced the consequences of her actions in its dramatic courtroom scenes. One of Meredith Grey’s harsh realities was that she’d used her daughter Ellis to commit insurance fraud in order to help out a young girl with cancer whose father was uninsured. While the act itself was irresponsible to her child, Meredith was fighting back against the unfair medical system and stuck to her oath to protect her patients. However, “My Shot” was so pivotal because of how many people came to her defense at her medical license hearing.
Karev, Webber, and Bailey (Chandra Wilson) all spoke in favor of Meredith and provided crucial support. Webber’s speech was particularly moving because he acknowledged the challenges Meredith had overcome professionally and personally. Meredith also called out one of the committee members for their involvement in Derek’s death, which was incredibly powerful. “My Shot” was an amazing reflection of Meredith’s character development since the Grey’s Anatomy pilot, but it also highlighted issues in the real world and the injustices of the American medical system.
1. Good As Hell
Season 17, Episode 13
Grey’s Anatomy season 17 implemented the events of COVID-19 into its storyline, and after Meredith caught it, entered into a comatose state. In “Good as Hell,” her COVID-induced coma created some weird delusions. Everyone Meredith saw on the beach in Grey’s Anatomy was an old face, but the most bittersweet person she greeted was her late husband, Derek. Derek’s unexpected cameo provided the beautiful and emotional closure that Meredith needed, and his presence motivated her to wake up.
This episode changed Grey’s Anatomy forever because it brilliantly displayed who Meredith was overall. The development she experienced throughout the show was apparent in the beach scenes, and reuniting with those familiar figures was a fantastic way of demonstrating it. “Good as Hell” acknowledged how different the show had become over the years by reflecting on COVID-19 and how it affected its characters while still reinforcing the core values that made it such a success in the first place.
