Jon Snow was my overall favorite on the show by the time the series was over. Though I'll admit, I didn't care about him as much at the start. He's the supposed bastard son of Eddard Stark, and he has many half-siblings. While him and Robb got along, he was often jealous of his legitimate brother and the fact that Robb had a mother, and Jon did not.
But all the Stark children adored their father, Ned Stark. Ned seemed to be willing to tell Jon the truth about his mother, after he joins the Night's Watch and takes a non-reversible vow. But Ned dies before the two could reunite again.
Jon Snow proves to be a great asset to the Night's Watch. He's good with a sword, he's got a strong moral code, and he has a giant direwolf named Ghost as a pet. He even gets Lord Commander Mormont's family sword for saving Mormont's life from a wight.
But he gets captured by the Wildings and he pretends that he wants to defect. He falls in love with Ygritte, whom dies during a battle after he goes back to Castle Black as a crow. A very touching but sad death there.
Despite being enemies, Jon Snow and Mance Rayder get along very well. He tries to advise Mance when Stannis Baratheon has him as a prisoner. And he kills Mance in an act of mercy when Stannis tries to make an example of him.
He rises as Lord Commander of the Night's Watch. But he knew the Army of the Dead, and not the Free Folk were the real threat to the Seven Kingdoms. He sees the Night King and he knows more than anyone else, how hopeless the fight is. Then his own men stab him to death. Then the Red Woman brings him back to life.
And he leaves the Night's Watch and fights the Boltons. I really loved seeing Jon coming back to life, and I really enjoyed seeing him fight for House Stark. He becomes King in the North, but in truth he was born Aegon VI, as his father Ned was really his uncle and his aunt Lyanna was really his mom. And Prince Rhaegar was his actual dad.
He begs his aunt Daenerys Targaryen for help and for the dragonglass to help defeat the Night King. They do that, topple Cersei, fall in love, and have a huge ups and downs in politics. He swears that she is "his Queen" always.
Then he stabs her when she defeats Cersei and it's apparent Dany is going to make the world a worse place. I really thought Drogon was going to kill him, but the dragon is a lazy detective. Makes it seem like Drogon thought the Iron Throne killed his mom.
And Jon is exiled to the Night's Watch, but might become the new King Beyond the Wall. I hated this ending (though I was glad Ghost survived) and I really wanted to see Jon rule as Aegon VI, with or without Dany by his side. I'm glad he lived past the end, but... it's bittersweet.