I absolutely loved the ending. The way Lelouch took the world's hate upon himself to help it recover from the damage Britannia had done reminded me of what Batman did at the end of The Dark Knight, and the way Lelouch passed the mantle of Zero to Suzaku reminded me of John Blake being implied to be the next Batman at the end of The Dark Knight Rises.
I didn't catch the implications of Lelouch still being alive, but after I finished it one of my friends who's really into the show told me about the theory, and it makes sense to me. Part of me hopes he's alive, but part of me would prefer that he be truly dead since it makes his sacrifice more emotional.
I think the parallels between Code Geass and Death Note are also interesting. Lelouch and Light are both bored, brilliant, and ambitious high schoolers who have a great, terrible power unexpectedly thrust upon them. I believe that the difference in outcomes for the protagonists and the people around them/the world (with a wholly negative and tragic one occuring in Death Note and a still tragic but ultimately good in Code Geass) is mainly due to Light essentially being a sociopath, whereas Lelouch has a conscience and is much more emotional, even if he tries to hide it.
Recently completed: Jacob Frye (AC Syndicate), Bucky Barnes (Captain America: TFA), Mako (Legend of Korra), Spike Spiegel (Cowboy Bebop), Newt Scamander (Fantastic Beasts)
In progress/planned: Roy Mustang (FMA: Brotherhood), Aldo Raine (Inglourious Basterds), Han Solo (Star Wars Ep V), Tommy Shelby (Peaky Blinders), Steve Rogers (Captain America: TFA), Jonathan Byers (Stranger Things)