An ending where Gracia had a little brother or sister for Elicia!
Seriously, though, I"m a manga/Brotherhood fan. For me, [SPOILING AHOY], the idea that Ed and Al would end up on a different world where none of the other people they love or care for were is epically sad, especially since Ed went from declaring that he wouldn't kill a human to taking the lives of others with less and less regard for that action. I know that in the world, soldiers and other people face this choice all the time, but this is Edward Elric, master of the unexpected third option, which is what he does in the manga. He still loses something important, but keeps his principles and his moral code, AND his friends and family.