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.
Oh! Though choice. The 1st anime is a bit darker than brotherhood so it would make sense that the ending would be more deep (is that the right word to use).
But the brotherhood ending makes more sense to me so....
I'm going with the brotherhood ending.