Lexa watching Clarke sleep
Watching over someone else as they sleep could mean a lot of things, in this case, this was further proof of the lingering affections that Lexa had started to experience for Clarke. This is a split second glimpse of something that would set the scene for an epic revelation further on in the season, so looking back at this is a lovely reminder of what is to come.
Zeke willing to die for Raven to live
Raven is someone who is constantly risking her life for her friends without a second thought. At her core, Raven cares about her people and death was never a dealbreaker. So her finding someone who would be willing to literally die for her after knowing her for a few weeks is finding someone that she deserves to be with in the future. But also this is another example of who Zeke is, a character we were lucky to meet and who is everything we all have been waiting for.
Bellamy and Clarke's Season 3 Journey
As emotionally compromising as Season 3 was, for Bellamy and Clarke's relationship it might have been the best turn of events. In terms of leading their people and just being themselves, those two needed one another to make any of that work. Their first prolonged separation put it all on the line, proving that The 100 very much is about Bellamy and Clarke's relationship with one another. Also, there was too much touching and too many looks for there to be any doubt about the startlingly way that "losing" Clarke made Bellamy come to terms about some feelings.
Monty and Harper showing everyone how to live
Monty and Harper lived life instead of just hoping to survive the next big obstacle in their way. Their memory goes hand in hand with their legacy and this scene where they foreshadowed their future gains more value because of exactly that. At their simplest times, they were a farmer and a survivor that wouldn't let the destruction around them affect who they were. At the end of the Book One, Monty and Harper came out as the true good guys and their love for each other and their family conquered all.
Lincoln and Octavia pulling strength from one another
Lincoln and Octavia were all each other's center and it could even be argued that Octavia's humanity died out with him. These quick flashes of comfort between the two are great indicators of romance that doesn't have to be over the top. A simple gesture fueled these two to survive the next war that came their way, they truly found their strength through one another.
Bellamy and Clarke's Season 4 Journey
The end of the world on The 100 means figuring out where you stand, with Bellamy and Clarke finding peace in their places alongside each other. This was a true love letter of what would be in a perfect world where a time jump didn't mean offscreen content. Had Clarke gone up to space with everyone else there is no question in anyone's mind that she and Bellamy would be together in under a year. Season 4 was leading up to that revelation, with the season finale teasing how much lines were starting to blur for them. Not only was seeking each other's touch almost a reflex to them, now they were in a place where they were planning what six years of peace would look like and for Bellamy and Clarke it meant them together.