It's funny that you mention Chrno Crusade. I really liked it but the ending just made it impossible for me to ever rewatch it. Like I would start rewatching it and then the ending would pop into my head. Which then made me just say NEVERMIND and turn off the dvd. It's a shame since I bought it too
But I guess all I'm trying to say is...I'd make it a happy ending. That's all it would take for me to watch it again.