So most of us watched "Death Note" and it was a great anime but there's the theory that Light became a shinigami. **Spoilers alert**.
It was sad how Light ended up being killed, but Ryuk told him before he would die by his hand. There's multiple pieces of evidence that Light became a shinigami. In the movie "Death Note Relight 1: Visions of a God" at the beginning of the movie there is an unknown shinigami which no one knows looking for Ryuk. When the shinigami gets to Ryuk he asks him for his story in the human world.
1. The unknown shinigami in exchange for the story gave Ryuk an apple which is weird that he knew since Ryuk was more like a "lone wolf" and the others wouldn't know about it. When he tossed him the apple he tossed it how Light used to throw Ryuk the apples.
2. When the unknown shinigami was walking the stairs to get to Ryuk he had the same walk as Light before he died.
3. Light tricked Rem and got her official Death Note which she used to extend her life span, which no one else had except him and maybe cause he got it, it had something to do with his transformation.
5. When Ryuk was telling the story he wanted to show the unknown shinigami the place where he wrote Light's name and he started talking like he was referring to the shinigami directly "You were never a god. You were just..." and his words were cut when he noticed the shinigami already left before he could finish the story. Ryuk started talking about seeing something the shinigami will never forget if he goes to the human world, finishing his sentence like he is still referring to the shinigami but he called him Light "And you get to see something you won't forget for the rest of your life. Am i right...right?...Light".
6. As said above the shinigami left before Ryuk could finish his story, maybe it was cause he already knew how it ended since the shinigami was actually Light trying to remember himself and with Ryuk's story he manged to.
7. The unknown shinigami in the movie wears a tie around his head like the one Light wore every time when he went to school and had a bag on his shoulder like Light's school bag. Plus the shinigami had a similar jacket to the one Light wore when he died.
Well there are probably more pieces of evidence that could show that Light probably became a shinigami but this is just a theory, you choose if you want to believe it or not.