As Jon Snow takes command of the Nights Watch, he convinces Stannis Barratheon to loan him his ships so that he may talk the freefolk into moving south of the wall before the Night King makes his attack. Stannis reluctantly agrees and Jon, along with Tormund, Ed and a handful of Crows head off to rescue the wildlings from being slaughtered.
After being enemies for centuries, it was not easy for Jon to win the trust of the elders but Tormund manages to talk some sense into some of the leaders who agree to sail on the ships and become allies against the White Walker Army. No sooner than the agreement is met that the Night King begins his assault on Hardhome, holding nothing back as his swarm of his undead army prey on Crows and wildlings alike.
Hardhome is one of the most significant battles in the Song of Ice and Fire saga mainly because it is the first time that the true strength of the Night King’s Army is revealed. This battle is also where Jon Snow discovers that apart from Dragonglass, the White Walkers are also vulnerable to Valyrian steel when he manages to take down a White Walker general with Longclaw.

Apart from being an action packed battle with the sheer volume of fighters, Hardhome was also an emotional one and a thought provoking one. It implies a connection between Jon and the Night King who, on multiple occasions establishes eye contact with the Lord Commander as if challenging him to engage in battle further. Night King also reveals to Jon the extent of his powers when, as they flee to the relative safety of the wall, he commands the dead to rise and join his forces. Jon and his men also witness how strong and how feral these dead soldiers can be as they manage to retain the fighting skills they had when they were alive as they prey on the living.
While the Night King was mostly a jerk for showboating in this battle, it was very interesting because it showed two sides to Jon Snow, the leader who puts other people first, and also an imperfect soldier who bleeds and falters in the face of danger. Yet at the same time, this battle builds up the momentum on the Great War and ominously projects the ruthlessness of the Night King and his thirst for revenge.
All in all, Hardhome makes fans wonder whether Jon Snow was indeed the Prince that was Promised in the books because he ticked off all the qualities of a person who will sit justly on the Iron Throne, and perhaps put an end to the Long Night. Hardhome was an exciting and hard fought battle and one that would always remain my favorite because it was masterfully executed and built up characters to root for as the series progresses.
PS. Towards the beginning of the episode, Sam made a quite a telling foreshadowing when he mentioned that Jon Snow always came back. Little did fans know at this point that it would be a reference to his eventual resurrection at the hands of the Lord of the Light.