What are some of the fictional stories (from any medium) that really got you emotionally invested in them and affected you in ways most stories don't? Stories you built up an emotional attachment towards?

For me, there are quite a few, but the one that stands out above all is Clannad. I got to know it in mid-October and up till now, it hasn't gone out of my mind, and it doesn't seem like it has any intention to do so anytime soon. I choke up every time I watch any of 4 particular scenes near the end, without fail.

I love this kind of story and would like have more such connections, and thus I would like you to share with me, storylines you have an emotional attachment to.