Over its seven season (and 100 episode) run, CW's The 100 has entertained fans, broken their hearts, and made them think. The best episodes of the series do a combination of all three. Centered around Clarke Griffin and her friends, The 100 explores what happens when humanity has a second (and third, and fourth) chance to survive again on a hostile planet.

RELATED: The 100: 5 Times Clarke Was The Better Leader (& 5 It Was Bellamy)

Now that the series has come to an end, fans look back and ponder which episodes rank among the best.

S1E13 We Are Grounders Part Two (8.9)

The 100 Season 1 Finale

Though season one remains a favorite amongst long time fans, this is the only episode from the freshman season to make it into the top ten. It also happens to be the season one finale.

In the episode, the conflict with the Grounders comes to a temporary end  as the Arkadians use every piece of technology in their arsenal to secure a win - including the rockets of the dropship. Of course, just when the teenagers think they claim victory, they find themselves gassed and taken to a new location. A whole new enemy is introduced with the brief tease, leaving fans wanting more.

S2E08 Spacewalker (8.9)

The 100 S2E08 Spacewalker

Though Finn isn't anybody's favorite character, his backstory in this episode ties in with Raven's, who is a fan favorite. The big reveal of the hour is that Finn didn't really earn his nickname of "Spacewalker."

Instead, Finn ends up in prison on the Ark because Raven Reyes take an illegal spacewalk. It's Raven who costs the Ark months of oxygen when she does, and Finn taking the blame is one of the many ways she feels tied to him. When Lexa says she'll only consider peace with those from the Ark if Finn is punished for his crimes against the Grounders, it creates a heart wrenching situation for both Raven and Clarke. Clarke ultimately kills Finn herself so the Grounders can't torture him, creating a rift between her and Raven for a while.

S3E03 Ye Who Enter Here (8.9)

Raven And Gina In The 100 S3E03

Initially, the third season sees Clarke trying to live on her own and stay far away from both the Grounders and the Arkadians. That leaves a little more room for stories with other characters.

In this case, Bellamy Blake and Raven get the chance for a little more story time as the two work to make Mount Weather habitable for the Arkadians who were members of Farm Station. When Bellamy is warned by Echo of an imminent attack at Polis while Lexa discusses making "Skaikru" official, he sets out to help, leaving Mount Weather vulnerable to attack. Raven and Sinclair try to stop it, but Azgeda, working with Mountain Man Emerson makes sure the mountain stronghold self-destructs, killing the inhabitants of Farm Station, and Bellamy's girlfriend Gina.

S5E03 Sleeping Giants (9.0)

The 100 S5E03 Sleeping Giants

The fifth season brings a whole new group of people into the picture to cause conflict. Those people are the inhabitants of an Eligius prisoner ship, and they're led by Charmaine Diyoza.

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When Diyoza has her people grab Clarke for interrogation, Clarke is initially not very responsive. It's Diyoza's insistence that Madi be shot on sight that has Clarke answering any question Diyoza asks. Of course, Bellamy and his friends attempt to come to her rescue just in time - by bartering with the lives of the nearly 300 people still in cryosleep on the ship.

S5E12 Damocles Part One (9.0)

The 100 S5E12 Damocles Part One

The conflict between the prisoners and Wonkru comes to a head in the season five finale. McCreary is able to ambush Wonkru, and their forced retreat makes Octavia's soldiers begin to fall apart. When Madi wants to help, Clarke is vehemently against the idea.

Eventually, however, Madi is able to convince Clarke that they're on the wrong side of this conflict as they stay with the prisoners. Clarke allows Madi to go with Echo, Raven, and Shaw to help Wonkru unite again. When she does, she stays behind to make sure McCreary can't stop them.

S4E10 Die All, Die Merrily (9.2)

The 100 Die All Die Merrily S4E10

The end of the fourth season headed steadily toward the end of the world (again). Luckily for those of humanity still on Earth, the Second Dawn cult left a bunker in Polis that they can use - if they can survive long enough to claim it.

Grounder tradition has Nightbloods compete in a conclave to become the leader of the coalition. Now, it's not Nightbloods competing, but instead, a representative from each clan. The prize isn't becoming heda, but deciding how the bunker will be used. Octavia represents her people in the fight, and in a surprise upset, she defeats Luna in the end to claim the bunker. Octavia further surprises everyone by deciding that all of the clans should share the bunker equally. It's the beginning of Wonkru, but also a snapshot of just how underhanded humanity is when it comes to survival as members of the conclave cheat and members of Skaikru barricade themselves in the bunker.

S2E16 Blood Must Have Blood Part Two (9.3)

The 100 Blood Must Have Blood Part 2 S2E16

Heading toward the best of the best is this season two finale - which also happens to be the best of the second season. In it, the conflict between the Grounders, the Arkadians, and the Sky People comes to a head.

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In the previous episode, Lexa abandons her deal with Clarke because she makes a deal with the Mountain Men to keep her people safe. When Clarke attempts to negotiate with the Mountain Men without Lexa's backup, the results are disastrous. She and her friends are left with no choice but to take drastic measures. Together, Clarke, Bellamy, and Monty all decide to open Mount Weather to the elements, killing everyone inside who isn't a Grounder or Sky Person. The decision haunts them all for a long time.

S4E13 Praimfaya (9.3)

Season 4 Episode 13 of The 100.

It seems like the core cast of characters can never catch a break, can they? In the season four finale, a small group finds themselves separated from the rest as the death wave of radiation hits the Second Dawn bunker. They have no choice but to try to leave the planet.

Clarke, Raven, Bellamy, Monty, Harper, Murphy, Echo, and Emori team up to get the rocket at Becca's lab ready to launch before the death wave reaches them. While the others are able to go to space, Clarke is left behind to make sure the rocket goes up. Luckily, despite a few burns, her Nightblood offers her protection from the worst of the radiation, and for six years, she lives alone with a young Nightblood she adopts.

S7E08 Anaconda (9.4)

The 100 Calllie Anaconda

The second highest rated episode of the series isn't a normal episode of The 100. Instead, it's a flashback episode set nearly a century before the events of the show take place.

"Anaconda" takes the audience back to the original "Praimfaya" as radiation and nuclear missiles overtook the planet. It centers on Callie Cadogan, the woman who Becca befriends and hands her mind drive (which will become the Grounder Flame) off to. The episode is chock full of nods to the Grounder nations the audience knows and makes for an intriguing backdoor pilot to a prequel series.

S5E13 Damocles Part Two (9.6)

The 100 Eliza Taylor as Clarke Griffin, Bob Morely as Bellamy Blake

The second part of the season five finale is a hopeful one - and one that a lot of fans would have been happy with as a series finale. That's likely why it ranks so high amongst all of the episodes of The 100.

In the hour, the fighting on Earth between the Eligius prisoners and Wonkru finally stops. Madi accepts her role as Heda and Diyoza and Clarke come to an agreement about the future of the human race when McCreary ignites a bomb that prevents them from being able to stay on Earth. The Eligius prison ship is used to get as many off the planet and into cryosleep as possible for a long journey across the stars.

Monty and Harper decide not to sleep, but to chart a course to a planet to give humanity a second chance, living their lives in the peace they always wanted.

NEXT: The 100: 10 Questions We Still Have After The Series Finale