Grey's Anatomy is not just a show based on medicine. At the heart of most stories is Meredith Grey (Ellen Pompeo), a General surgeon who has faced a lot of tragedy over the years. However, despite all this, she has managed to become one of the strongest female characters on TV.

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Meredith has proven time and time again to be a pillar in the Grey-Sloan community, taking in "strays" and providing emotional comfort when needed. Yet, there were also times when fans wanted to scream in frustration as the surgeon allowed her personal feelings to cloud her judgment. Here are the 5 examples of when Meredith was a good friend (& 5 when she wasn't).

WORST: Sleeping with George

George looks on in Grey's Anatomy

Fans were shocked to see Meredith and George (T.R. Knight) hook up in the episode "What Have I Done To Deserve This?". However, everyone knew it was going to be a disaster since Meredith had just gone through a hugely traumatic event. Let's not forget the residual feelings for McDreamy either.

Quite frankly, George should have known Meredith was not in the right frame of mind after the bomb. At the same time, Meredith had been well aware that George had feelings for her so it wasn't surprising he was hurt when she began crying. Even though she profusely apologized, the incident ended up fracturing their friendship as George moved out.

BEST: Helping Alex with his exam

Alex (Justin Chambers) and Meredith's friendship started when she helped Alex to study for his board exams. In the episode "Grandma Got Run Over By a Reindeer", Meredith decides to help Alex study for his exam after noticing how disheartened he is at work. She asks Bailey (Chandra Wilson) if she can miss a surgery to help him out.

Although they all understand Izzie's (Katherine Heigl) anger, Meredith jumps to defend Alex. She tells her friends that she considers them her family, including Alex, and she would jump at the chance to help them too. In a final request, Meredith asks Izzie to put her anger aside and help him.

WORST: Causing a wedge between Jo and Alex

Alex And Jo

For quite some time, Meredith caused friction between Jo (Camilla Luddington) and Alex. Season 9 saw Jo and Meredith clash a lot over the General surgeon's harsh treatment. Jo had been furious with Meredith after realizing she was chosen to fail the appendectomy. Tensions between the two increased further when Alex began to date the (then) resident.

Jo didn't particularly like that Meredith had no personal boundaries. Meredith would often turn up at their house unannounced, kick Jo out of bed and encroach in on her life with Alex. Considering Alex is her best friend and was in love with Jo, Meredith should have treated her with more respect and tried harder to form a relationship.

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BEST: Becoming Alex's person

The bond between Alex and Meredith has never been stronger than it is now. Yet, there have been several moments over the 16 seasons that have been monumental. One of the first instances being in the episode "Take It Back", when she hugs Alex to stop him from beating up Shane (Gaius Charles). The other was her support through the Deluca (Giacomo Gianniotti) trial.

Fans were horrified when Alex beat up Deluca after misinterpreting a situation with Jo. Although she does the right thing by reporting him to Bailey, Meredith continues to vouch for Alex's character afterward. She also takes Alex in until he manages to get back on his feet. Not a lot of people would have done this so it shows how serious Meredith values his presence.

WORST: Fight with Cristina

One of the most ridiculous fights that occurred between Cristina (Sandra Oh) and Meredith came in season 10 when they argued about whose career was better. Meredith got annoyed at Cristina for insinuating she wasn't as good of a surgeon because she chose to have a family. As a result, Meredith began to try and compete with Cristina.

The fight escalated quickly between the friends to the point that it began to affect Meredith's work ("Two Against One"). When she was in an operation with Alex, Meredith begins to go off script and becomes reckless with her decision making. Later, Alex reprimands her for allowing her fight with Cristina to affect her judgment call.

BEST: Supportive in Cristina's PTSD

After the events of the Season 6 finale, the hospital took a long time to recover. When season 7 opened, Meredith and Cristina were shown to be repressing their emotions. The General surgeon also began to worry about her best friend when she noticed her putting more energy into wedding planning than surgery ("With You I'm Born Again").

When the other surgeons believed that Cristina was ready to operate, Meredith protested against it. Her intuition was proven right when Yang collapsed in the OR, paralyzed by fear ("Shock to the System"). Meredith showed fans why she was Cristina's person as she rushed into the OR and lied down with the cardiothoracic surgeon. She then waited patiently for Cristina to calm down before escorting her to the resident's locker room.

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WORST: Disappearing after Derek's death

None of her friends held it against her when she decided to take a sabbatical after Derek's (Patrick Dempsey) death. They knew she needed to heal in her own way so they understood why she couldn't stay in their home or go to the workplace where she fell in love. What they couldn't forgive was how she didn't get in touch with any of them to let them know she was okay ("She's Leaving Home").

For a whole year, she was deemed missing. Alex and Maggie (Kelly McCreary) were worried something could have happened to her as she kept ignoring everyone's calls. It was only on Thanksgiving that she did respond, telling Alex to stop calling because everyone was okay.

BEST: Giving Izzie her wedding

One of the kinder moments of Meredith and Izzie's friendship came in season 5 when she gave Izzie her wedding. When Derek proposed, Meredith asked Izzie to organize the wedding to help distract her from the chemotherapy. It does seem to help, with Izzie making her try on gowns and eat food samples.

However, Derek soon discovers that Izzie has another tumor which he cannot remove ("What a Difference a Day Makes"). With the risk of her dying, Meredith and Derek decide to give Izzie her dream wedding. Izzie was overjoyed by the sentiment, thanking her for giving up the venue.

WORST: Not allowing Amelia to say goodbye

Amelia and Meredith talking in Grey's Anatomy

Nobody could hold it against Meredith when she turned off Derek's life support. Everyone understood that she was so overcome by the shock that she didn't have time to consider anybody else. However, fans couldn't help but sympathize with Amelia (Caterina Scorsone) when she got upset at not being able to see her brother a final time.

In the episode "Time Stops", Amelia confronts Meredith about putting Derek's house up for sale. She also berates her for not calling her when Meredith found out the news, claiming she could have saved him. When Meredith says there was nothing anyone could do, Amelia gets upset about the fact that the General surgeon decided to turn the life support off without allowing her to say goodbye. As a result, their friendship was briefly strained.

BEST: Helping Jo with her divorce

Jo talking to Paul at the hospital in Grey's Anatomy

Jo and Meredith may not have had gotten off to a great start, but the pair have since grown closer since Meredith took Jo on as her resident. The mentor-mentee relationship had started as a favor to Alex but progressed when both surgeons grew to trust and respect each other's work. Yet, they solidified themselves as friends when Meredith protected Jo from Paul (Matthew Morrison).

This had to be one of the most touching moments in all seasons when Meredith and Alex raced to find Jo. The General surgeon hugs Jo after the resident found out Paul is trying to manipulate everyone into believing she is the 'bad guy'. Meredith refuses to leave her side as the former couple sign their divorce papers, protecting her as he begins to get aggressive again.

NEXT: Grey's Anatomy: 10 Things You Didn't Know About Meredith and Cristina's Friendship