I have a friend who consistently makes amazing characters, but there is one that stands out for all of us in the group and that is his elven wizard he played in the 5e game I ran for them. Game started at level 3 and went to 20 over the course of a year and a half, maybe two years IRL. I'm going to do my best to summarize this without going too in-depth. By the end of the game, only he and the NPC companion they picked up early on were the only original party members left but his story revolved heavily around two important story beats: living up to his grandmother's legacy, and saving his childhood best friend and love of his life.
His grandmother was a legendary hero who stopped helped to seal away a corrupt and maddened Solar angel bent on becoming the new god of death. The plot revolved heavily around these artifacts that all held pieces of the Solar's spirit. Before the start of the game, his wizard's home was attacked by an Orc warlord who had stolen his grandmother's circlet which hid one of these pieces of the Solar and laid a curse on his childhood friend. Part way through that game they discovered a piece of a lost piece of elven high magic that could cure any affliction but required the help of every member of the elven high shaman council to complete, one of which was the childhood friend's little sister.
Unfortunately, the spell was missing a piece and they tried it anyway. The friend was cured of this curse which had placed her in a coma and was slowly turning her into a plant, except it only cured her soul and caused her body to fade away as her soul and body were no longer the same. Now, an important piece of this is that before the game even started my friend and I had discussed what he wanted out of this plot thread, and he wanted it to be a bittersweet ending. So, he was able to save her, but in the end he still lost her. What I did not know until AFTER we played this out in-character was that this friend was inspired by a real-life friend that he lost to cancer. For him it was cathartic and helped him to process what had happened while also helping him feel that he honored his friend to the best of his ability. It was the first time I ever made a player actively cry.