Lennie Small from Of Mice and Men. When Lennie accidentally killed that woman because of his strength and then had to run away with George, it was already kinda fucked. But then you get to the part where George shoots Lennie in the back of the head because he knew he would’ve faced a much worse death otherwise. That ending was so damn sad but good. It really made me think about it for a while. I would also say the skeleton brothers from Undertale just because I played the pacifist route first and I loved all the characters. Papyrus still believed you could be better and then sans just accepted it and said “papyrus…do you want anything?” and then dusting off-screen.
It might seem silly, bit honestly. Entei from the third pokemon movie. I was four when it came out, and eight when I first saw it. At that time, I really wanted a dad and Entei was the perfect kind of father figure to me. Also, I looked a lot like Molly, the “adoptive daughter”, so it really hit me when he sacrificed himself, because she lost her dad a second time