For a show about friendship and science, The Big Bang Theory has some incredibly emotional episodes. This group of best friends became each other's family over the span of 11 seasons and have been there for each other through some of their darkest moments. Sheldon's personality traits, in particular, bring about plenty of harrowing moments because he's not always aware of what's going on around him.
But it's not just Sheldon. Howard has also been through hell and back in the sitcom and finally found his stride by the series' final season. From deaths to questions about life, The Big Bang Theory has as many emotional episodes as uplifting ones.
"The Closet Reconfiguration" (S6, E19)
For years, Howard's father issues have been a trigger in every tough decision he's had to make. Whenever he's in an argument with Bernadette, he brings up the "my dad left me when I was a kid" card to make Bernadette feel bad for him. Bernadette eventually stopped feeling sorry for him but things changed in season 6's "The Closet Reconfiguration."
Sheldon found an old letter addressed to Howard in his closet. Howard never read the letter but Sheldon did. It was from his father for Howard's 18th birthday. Howard was devastated that Sheldon read the card and told everyone what was inside because even Howard didn't know what it said. It was one of Howard's most human moments in the series.
"The Leftover Thermalization" (S8, E18)
It was devastating for the entire group when Mrs. Wolowitz died because it was so unexpected. To make matters worse, the power went out in her home, which meant that all of the food she had made and stored in the freezer was starting to thaw.
Knowing those were the last meals Howard would ever eat of his mother's, he invited everyone over and had a makeshift Thanksgiving dinner. Everyone came over and ate her food under candlelight. It was a sweet way to honor his mother.
"The Commitment Determination" (S8, E24)
In "The Commitment Determination," Amy and Sheldon were celebrating their five-year anniversary. While kissing, Sheldon mentioned The Flash TV show, which triggered Amy. He was the only thing on her mind while kissing but The Flash was on his. This left a bad taste in Amy's mouth.
By the end of the episode, Amy shocked everyone by telling Sheldon she needed a break from the relationship. When they hung up, Sheldon pulled out an engagement ring from his desk that he had been keeping for Amy. The idea of Sheldon and Amy ending their relationship when he was so close to doing what she dreamt of was heartbreaking.
"The Wheaton Recurrence" (S3, E19)
When Penny and Leonard first started becoming serious, Penny tensed up because it was obvious that Leonard was far more into her than she was into him. After he told her he loved her, she didn't know how to react because she wasn't sure she felt the same way.
While the group was at a bowling alley, Wil Wheaton reminded Penny that it wasn't fair to drag Leonard along if she wasn't interested in furthering the relationship. The realization was upsetting and she broke up with Leonard right there.
"The Stockholm Syndrome" (S12, E24)
The finale of was incredibly emotional. Not only did viewers find out that Penny was pregnant but the issues between Sheldon's selfishness and the group were more apparent than ever. Everyone was upset at Sheldon's egotism, which made Amy mad at her husband for hurting their friends. During his Nobel Prize acceptance speech, Sheldon threw out his prepared speech and thanked his friends instead. There wasn't a dry eye in the room.
"The Proton Transmogrification" (S7, E22)
Professor Proton was the host of a children's television show when Sheldon was going up. His real name was Arthur Jeffries and he was actually a real scientist. Sheldon ired Arthur for years and became friends with him after they met in line at a pharmacy.
Sadly, Arthur ed away from old age in the seventh season. Leonard broke the news gently to Sheldon and it hit him harder than he realized. Sheldon took a nap and when he woke up, he hugged Leonard tightly. It was one of the best Sheldon and Leonard moments.
"The Platonic Permutation" (S9, E9)
It took some time but Sheldon and Amy were able to be friends during their breakup. But when Thanksgiving rolled around, they both agreed to spend the day at the aquarium because they still had tickets from when they were dating.
It was while they were together that Amy realized she still loved Sheldon and wanted to be back with him. At the end of the day, Amy excitedly called Sheldon to tell him she wanted to date again but Sheldon turned her down. He told her that because of how badly she wounded him, he needed more time.
"The Status Quo Combustion" (S7, E24)
At the end of season 7, Leonard and Penny get engaged and talk about moving out, and the comic book store suffered from a fire. These were two massive changes in Sheldon's life that he was able to cope with. Sheldon doesn't handle change well and realized he needed to leave.
In a very upsetting scene, Sheldon ran away without telling anyone and headed for the train station. He was gearing up for a summer away visiting different train stations in America. Watching Leonard and Penny leave him at the train station was gutting.
"The Citation Negation" (S12, E9)
When Sheldon and Amy were working on potential award-winning research for Super Asymmetry, Leonard, Howard, and Raj helped them by checking their research against other sources. Sadly, Howard read a book by Russian scientists that debunked Amy and Sheldon's theory. For weeks, they thought they were on to something huge but it turned out to be a dead end. The news deflated the newly married couple.
"The Hesitation Ramification" (S7, E12)
Penny was over the moon when she finally booked a small role in NCIS. After trying to land acting gigs for years in California, Penny was finally on the road to success. Sadly, when it came time to watch the episode, she discovered her role was cut. With all of her friends and family watching, she was mortified. She decided after that night that acting was not for her and she didn't know what to do with her life. It was the lowest viewers ever saw Penny.