The series ended up with 171 episodes, which is quite a lot to watch in such a little time. So here is a list of some of my favorite episodes you should watch before it's too late!
season 1, episode 22
This episode reveals Katherine Pierce and begins a new era in the mythology of The Vampire Diaries. Also, there is that seen with Uncle John that is still traumatizing. But over all, the episode sets up Katherine who becomes important to the plot.
season 2, episode 8
This episode is filled with important moments (also foreshadowing for the arrival of the Mikaelson's). One of the biggest moments though is Damon sharing his feelings for Elena for the first time.
season 4, episode 15
One of the most emotional moments in the whole series is probably when Elena comes to terms with her brother dying and burning down her own house.
season 3, episode 19
That kiss scene with Never Let Me Go playing is all I have to say.
season 4, episode 23
In this episode, Elena fights Katherine and we find out who ends up with the "cure."
season 3, episode 22
Elena and Matt's wreck changes the path of the show forever and honestly it's worth a watch before it's too late. The whole episode is full of great moments that change the course of the show. There is also one scene that takes completely under water.
season 5, episode 11
Episode 100 was a milestone for the show. It was also a milestone for many characters. We find out the fate of a dying Katherine, Klaroline share a major moment, and several couples also are given special moments.
season 2, episode 2
Not only is this episode the beginning of Caroline's journey as a vampire, but it features the first major Stefan and Caroline moment.
season 3, episode 14
This episode deserves a rewatch if you ship Klaroline. It also is a major episode that makes the The Originals spin off possible.
season 2, episode 18
The dances were always some of the best episodes. Honestly, Elena and the Mystic Falls crew should have learned to avoid school functions all together. This one makes the list because of the outfits, Bonnie's magic and Alaric playing body host to Klaus.
season 1, episode 1
How could I not mention the first episode? Watch it after the finale if you really want to see all the references and how things have changed.
season 6, episode 22
Let's be honest, Elena's goodbye was an end of an era in the series. It's worth a rewatch.
season 3, episode 5
Hello hybrids.
season 6, episode 15
There was many character deaths in The Vampire Diaries, but Sheriff Forbes was a hard one to watch. The episode is a tearjerker and one filled with emotional moments (including frustration!) Notable moments include, Caroline turning off her humanity, Kai and Bonnie, and Stefan's poor timing.
season 4, episode 23
Another popular Klaroline episode! Also, it is truly shocking as many of them survived long enough to graduate.
season 3, episode 3
The Vampires Diaries had many flashback scenes, but none of them can match this episode. Honestly, can we all agree that if we were alive in the 1920's we would want to be in Rebekah's friend group? (Maybe as a vampire so we had a chance at survival.) Also, we learn how awful Caroline's dad is and how much hatred for vampires there is in the show.
season 4, episode 4
Why not include the college heavy episode in your binge watching list?
season 8, episode 15
Weddings are normally happy events, but that is rarely the case in this show. The fact Stefan and Caroline successfully said their vows is enough reason to rewatch this episode. Also Bonnie is epic in this episode along side the twins. Also, Caroline's wedding fashion is another great reason to rewatch this episode.
season 6, episode 21
Speaking of weddings, Jo and Alaric's is for sure worth of a rewatch. If you watch Legacies (which is free on the CW app) you will notice many scenes that later referenced in the series.
season 6, episode 8
Friendsgiving is in full swing and nothing goes the way it was planned. There is several Forwood moments and we find out more about Kai's situation. (Also, another important one to watch if you watch Legacies.)
There are plenty of other episodes that are also worth your time if you like the show. But this is a good starting list, especially if you are a fan of Damon and Elena, Caroline and Klaus, and Caroline and Stefan. Have fun watching!