Saddest Anime

I'm surprised Bokurano hasn't been mentioned yet. Don't want to spoil too much, but if what you're after is a bleak, hopeless, sad robot anime, I honestly think this one messed me up more than NGE ever did. It has meaningful moments and faint glimmers of hope, but overall is a very dark and depressing series. Not that it's bad- I think it's honestly an amazing story. But I wouldn't watch or read it unless you think you want that kind of thing.