Zero's Requiem:
https://www.youtube.com/watch?v=3Vw7cCrlSq0 This is the ending of the show, but the most impressive thing about this scene is everything that comes before it, Lelouch becomes emperor, and it seems he has become corrupted with power and will change the world by force, he attacks the rest of the world along with the UN/Black Knights, uses his Geass on Nunally, and takes the entire world under his command, you think here we have a dark ending about absolute power corrupting absolutely, we think Suzaku had died against Kallen, and Lelouch had won... Only for all to have been a plan of his own, to bring back Zero the peoples martyr and have Zero(Suzaku who is not actually dead because Spinzaku cannot die XD) kill him in order to bring about a real chance for peace. He has made himself the ultimate evil of the world and by having the whole world hate him, the world is united and then instead of revealing in that power he gives his life in order to make the world really have a chance for peace. Obviously the world isn't that simple but he chooses to bet on the people of the world despite having looked down upon them and used them with his Geass, he in the end set out exactly what he wanted to do, what is said exactly in the narration, he wanted to make a world in which his sister could be happy and in the end he does so.