It's no secret that "Grey's Anatomy" is one of the biggest shows on TV right now, and even if you don't watch it, you know someone who does. Chances are, you've also heard about the various tragic exits of some beloved characters. Whether the characters were killed off or simply left, fans miss them all, and in many cases, feel that their story was ended too soon. So, here are the top 10 "Grey's Anatomy" characters who deserved better endings. Of course, there are spoilers ahead!

10. Heather Brooks (Tina Majorino)

Heather was a part of a group of interns that arrived at Grey-Sloan Memorial Hospital in season nine. Though she had a relatively small role, Heather was a budding neurosurgeon, and Derek Shepherd took it upon himself to teach her. However, when a super storm struck Seattle, Heather's fellow intern Shane Ross sent her on an errand which had originally been assigned to him. This led to Heather accidentally stepping into a puddle of water that had electrical wires dangling in it. She was electrocuted, and Shane found her several hours later. Though she was rushed into surgery, the swelling in her brain was too great and she died on the table.

Heather hadn't even finished the second year of her internship before her death. The other interns didn't even have stories to share with her mother when she came to the hospital, and as shown through following episodes, they didn't mourn very long. Though she had many insecurities and was at first regulated to menial tasks by other doctors, she had so much potential both as a surgeon and character. Her death sent Shane spiraling into a nervous breakdown, and he left the hospital soon after.

9. Reed Adamson (Nora Zehetner)

Reed was one of the doctors who came in when the hospital (then called Seattle Grace) merged with another hospital, Mercy West. Though she frequently butted heads with the other doctors, she was skilled, quick-thinking, and competitive, and ultimately an asset to the hospital. She was the first person to be killed by Gary Clark when he began his shooting spree in season seven. He asked Reed where he could find Dr. Shepherd, and she informed him that he was in a staff-only area and refused to help him. He shot her in the head and continued on through the hospitals damage. Reed's best friend, April Kepner, discovered her body after slipping in her blood.

8. Henry Burton (Scott Foley)

Henry was frequently in the hospital because he suffered from von Hippel-Lindau, a condition that creates multiple tumors in the body. He met Dr. Teddy Altman by chance and told her that he planned on proposing to his girlfriend for her insurance, as he had none to cover his surgeries. After his girlfriend turned him down, Teddy decided to marry Henry herself she could pay for his surgeries. Though neither of them intended to develop feelings, after a few months, they started to fall for each other.

Henry began shadowing Teddy and watching her surgeries, leading to his decision to attend med school. However, before he and Teddy could discuss it, Henry began coughing up blood and was rushed into surgery. Teddy couldn't operate on him because they were married, so she had her protege Cristina Yang perform the surgery. Unfortunately, the tumors had eroded too much of his heart and pancreas, and he did not survive the surgery.

7. Susan Grey (Mare Winnigham)

Susan Grey was Meredith's stepmother and Lexie's mother. She and Meredith had never met because Meredith and her father, Thatcher, hadn't spoken since he and her mother got divorced. Susan tried to connect with Meredith, bringing her groceries, trying to bring Meredith into the family. Although Meredith initially rejected Susan's attempts, she was happy to have a mother who was protective rather than pushy.

Susan was admitted to the hospital because of hiccups that wouldn't go away. Even after being treated they wouldn't stop. She hiccuped through the entire procedure. She had to return to the hospital several times, first after getting an infection from the surgery, then after the antibiotics failed and let to her becoming septic. She was rushed into surgery but sadly died on the table, leaving behind her two biological daughters and leaving Meredith feeling alone once again.

6. Teddy Altman (Kim Raver)

Teddy was Dr. Owen Hunt's friend and fellow veteran whom he hired due to her impressive skills as a cardio surgeon. Although she had feelings for Owen, she continued working at the hospital and mentored Cristina Yang. She married Henry Burton in order to help him pay for his surgeries suing her insurance. When he died on Cristina's operating table, she was devastated and made Cristina repeat the details of the surgery to her over and over for weeks. She also blamed Owen for Henry's death. Thankfully, they eventually reconciled.

Teddy was offered a position to work within the army again, but she turned it down in order to stay with Owen when his relationship with Cristina became rocky. Owen, as the current Chief of Staff, fired her, which left her free to pursue her dream.

5. Izzie Stevens (Katherine Heigl)

Izzie was part of the original group of interns on the show. She, George, and Meredith all moved into Meredith's house together. In order to pay for medical school, she became a model, and although she didn't want her coworkers to know that, they eventually found out. However, Izzie stood up for herself and proved that she was a force to be reckoned with.

She fell in love with a patient, Denny Duquette, Jr. and she risked her career to get him a heart transplant by cutting his LVAD wire. Despite receiving the transplant, Denny died hours after his surgery. He left Izzie (who he proposed to right before he died) a huge amount of money, which she used to cover a patient's medical bill and open the Denny Duquette Memorial Clinic. A while after that, she began to see Denny and "speak" with him. This was the first symptom of the brain tumor she eventually discovered she had developed. While she was fighting off the cancer, she married Alex Karev. However, after shortly after she returned to work, she made a potentially fatal mistake and was fired. Despite her friends and family begging her to stay, she left Seattle.

4. George O'Malley (T.R. Knight)

George is also one of the original interns. He was very sweet but also awkward, and had a huge crush on Meredith. He was given the nickname "007" after being the first of the interns to be involved in the death of a patient. However, he quickly earned the respect of the entire hospital after single-handedly saving a patient while trapped in an elevator that had broken down.

Right before his death, George joined the army as a trauma surgeon. However, he was hit by a bus after pushing a woman out of harm's way. When he was brought to the hospital, his injuries made him unrecognizable to his friends. He told Meredith who he was by tracing "007" on her hand. George was going to go on to do incredible things, but his life and time on the show were cut tragically short.

3. Mark Sloan (Eric Dane)

Nobody was rooting for Mark Sloan when he first made an appearance. He was Derek's best friend, and Derek's wife Addison had cheated on Derek with him. Mark's first act upon arriving in Seattle was to flirt with Meredith Grey, which earned him a swift right hook from Derek. Since then, Mark made his way through the women of Seattle Grace, earning him the nickname "McSteamy." During his time on the show, Mark discovered he had a grown daughter (who was pregnant) and had a brief relationship with Callie Torres (which resulted in their daughter Sofia, who Callie now shares custody with her ex-wife). However, as the seasons progressed, he began to settle down, especially when he began to fall for Lexie Grey, Meredith's half sister.

Mark died in season nine from complications of his injuries from the season eight plane crash. He was in a coma for a month before Callie and Derek took him off life support.

2. Lexie Grey (Chyler Leigh)

If I could only choose one fictional character to bring back to life, I would choose Lexie Grey. She appeared out of nowhere and introduced herself to Meredith as her half-sister Though she was initially hard to like, she and Meredith eventually bonded and became close. She died while trapped under a piece of the airplane after it crashed.

After her death, Lexie is only mentioned a few times. While we got to see nearly an entire episode's worth of memories of Mark, Lexie is hardly brought up or spoken about. She was extremely bright and kind, and she was really the only family Meredith had. Her death is made more painfully by the fact that, several seasons later, Meredith finds out she has another half-sister, who moves with Mere and her sister-in-law, Amelia. Lexie should have been a part of that sister squad.

1. Derek Shepherd (Patrick Dempsey)

Derek and Meredith have had their ups and downs since the series began. He was an attending surgeon when she was just an intern, but before the realized they were coworkers, they met at a bar and had what they thought would be a one night stand. Instead, that one night evolved into a twelve season long relationship. They got married by writing their vows on a Post-It, adopted a baby, and had two biological children after that. However, Derek didn't get to meet their third child. He was in a horrific car accident and died from complications of a brain injury. He had stopped on his way to work because he saw the wreck of a car accident. He able to save everyone else who survived the wreck, but as he was getting into his own car, he was hit by an oncoming truck. He wasn't taken to his own hospital, and there wasn't enough people on staff to help him. Meredith was forced to take him off life support, and the show has not been the same since.

It's become a joke amongst fans of "Grey's Anatomy" that we shouldn't get attached to characters or couples because they never stay long. Sometimes we can accept it and move on, but other time it completely alters the course of the show, even if it was the actors' choice.