Reaching 100 episodes is increasingly rare in today's overcrowded TV landscape, and on Jan. 23, The Vampire Diaries becomes only the third wholly contained CW drama (7th Heaven, Gilmore Girls, One Tree Hill, Smallville, and Supernatural all first aired on The WB, while Gossip Girl and 90210 qualify) to hit the 100-episode mark.
Along the way, The Vampire Diaries has turned its core triumvirate into pop culture icons, served as the launching pad for a new generation of stars, inspired a thrilling spin-off in The Originals, and recalibrated everyone's expectations for how quickly a show can — and should — power through storylines.
And it's those attention-grabbing, jaw-dropping, and ultimately game-changing moments (presented in chronological order below) that prove to be the hardest to shake.
1. Stefan kills Vicki.
Season 1, Episode 7 ("Haunted")
It's essential for any show that deals in death to establish, as quickly as possible, that main characters are very capable of dying. So TVD put Vicki on the chopping block and, in staking Mystic Falls' first cautionary tale, declared everyone was fair game for the Grim Reaper.
2. Elena accidentally helps Stefan off the wagon.
Season 1, Episode 17 ("Let the Right One in")
Elena's love for Stefan was tested early in their relationship when he was grievously wounded and she offered up her blood to save his life. Unfortunately for Elena, this selfless sentiment reignited Stefan's uncontrollable thirst for human blood (he'd been living off animals for centuries), foreshadowing his serious struggles with sobriety.
3. Damon and Elena's first dance.
Season 1, Episode 19 ("Miss Mystic Falls")
Any love triangle worth its salt needs to offer indisputable evidence for both suitors, and the Delena 'shippers claimed their first victory in the ongoing war against Stelena when Damon filled in as Elena's Miss Mystic Falls escort because an off-the-wagon Stefan was too busy feeding on the competition.
4. Katherine blows up Elena's life.
Season 1, Episode 22 ("Founder's Day")
Katherine had, actively and passively, been causing trouble since the pilot, but fans truly got their first taste of her manipulative ways — and TVD's ability to craft a crazy cliffhanger — when Katherine posed as her doppelgänger, Elena, and kissed Damon before slicing up John Gilbert.
5. Katherine turns Caroline into a vampire.
Season 2, Episodes 1 and 2 ("The Return" and "Brave New World")
Katherine continued to cut a swath through Mystic Falls and used Caroline – who'd been fed Damon's blood to heal from a car accident — to send a message to the Salvatore brothers by turning her into a vampire.
In retrospect, this was the single best thing Katherine has ever done because it transformed the overachieving cheerleader into a badass vampire, and one of the best characters on TVD.
6. Elijah arrives in Mystic Falls.
Season 2, Episode 8 ("Rose")
Elijah, Rebekah, Klaus, and the rest of their immortal clan have become so integral to Mystic Falls mythology, it's easy to forget that there was a time when the Mikaelsons weren't driving the plot.
The original vampires arrived one by one, with Elijah leading the charge to find the Moonstone, and reveal, in one seriously slick scene, that killing an Original is no easy task.
7. Klaus kills Aunt Jenna.
Season 2, Episode 21 ("The Sun Also Rises")
No disrespect to the overpopulated graveyards of Mystic Falls, but there has not been a death, before or since, that matches the emotional shockwave trigged by losing Aunt Jenna. Much of that stems from the fact Jenna was truly an innocent bystander that Elena couldn't protect from becoming Klaus' collateral damage.
8. Tyler becomes a hybrid.
Season 3, Episode 5 ("The Reckoning")
Tyler spent so much time worrying about accidentally setting off his family curse and transforming into a werewolf that it never occurred to him there was a fate worse than that. Poor Tyler learned the hard way when Klaus turned him into his hybrid bitch-boy, alienating Caroline and resulting in his eventual exodus from Mystic Falls.
9. Klaus flips Stefan's humanity switch.
Season 3, Episode 5 ("The Reckoning")
In order to keep those he loved safe, Stefan agreed to re-embrace his Ripper roots and join Klaus on a killing spree. But every sip tasted of remorse until Klaus caught on to his protege's penitence and forced Stefan to turn off his humanity, making him an unapologetic murder machine.
10. Alaric gets dark and immortal.
Season 3, Episode 16 ("1912")
Alaric was revealed to be the mysterious Mystic Falls murderer (his psyche split after one too many Gilbert Ring resurrections) with something called The Darkness acting as the Hyde to Alaric's Jekyll.
This kicked off one of the strongest run of episodes a single character has ever had on TVD as Esther Mikaelson then got her claws into Alaric and transformed him into an Original Vampire, tasked with wiping out her children. Rebekah then realized her mother had linked Alaric's life force to Elena's and killed her to eliminate two birds with one stone. That led to the death of Alaric and the rebirth of Elena. But more on that in a minute.
11. Kill an Original, their entire line dies.
Season 3, Episode 18 ("The Murder of One")
After learning a White Oak Stake (whittled out of the tree from which vampires derive their immortality) is the only way to kill an Original, the gang stumbled onto a major gift with purchase when they drove the stake into Finn's heart. Turns out, when you kill an Original, you also wipe out their entire line.
A fact that made killing Klaus basically impossible since Stefan, Damon, and Caroline are part of his illustrious lineage.
12. Elena is turned into a vampire.
Season 3, Episode 22 ("The Departed")
Because of her relationship with the Salvatore brothers, Elena had previously entertained the idea of becoming immortal, but made a very conscious decision to live out her mortal life. Rebekah had other plans, however, as she diverted a car carrying Elena off the road in a bid to kill Alaric, who had his life force linked with hers.
What Rebekah didn't — and couldn't — know was that Elena had Damon's blood in her system, turning her into a vampire and forever altering the trajectory of the show.
13. Jeremy becomes a hunter.
Season 4, Episode 12 ("A View to a Kill")
Jeremy's flirtation with the supernatural, both romantically and professionally, was upgraded to a full-time job when he became one of The Five and officially assumed the mantle of vampire hunter. Not an ideal occupation when your sister is undead.
14. Klaus impregnates Hayley (with a spin-off).
Season 4, Episode 16 ("Bring It On")
What was meant to be a one-night stand has blossomed into so much more as Klaus proved to be as fertile as he is deadly, spawning a baby and a spin-off.
15. Katherine gets force-fed The Cure.
Season 4, Episode 23 ("Graduation")
After spending ages traversing the globe in search of The Cure (it defangs vampires and hybrids alike) so she could use it to barter for her freedom from Klaus, Katherine learned why people have long cautioned "Be careful what you wish for."
Before she could exchange The Cure for an eternity out from under Klaus' watchful eye, Elena forced Katherine to digest the mysterious medicine during a particularly brutal fight, making her human — and susceptible to the common cold, as we learned in Season 5.
16. Elena says those Three Little Words.
Season 4, Episode 23 ("Graduation")
Damon may have said it first, but it was so much more significant when Elena said, "I love you" since it was uttered after she broke the sire bond and after he laid his soul bare in front of her.
17. Stefan is Silas' doppelgänger.
Season 4, Episode 23 ("Graduation Day")
The doppelgänger mythology has been a part of TVD's world since Season 1, but most of us assumed Katherine and Elena were the only instance of this super rare occurrence. We could not have been more wrong.
Not only was Stefan revealed to be Silas' doppelgänger, but it turns out Elena and Katherine were actually descendants of Amara, Silas' first love, meaning this fated lovers line continued to connect for centuries.