Storytelling endings

I just finished reading a manga fantasy series that was firmly grounded in the real world, and at the end, I was crying.  I'm pretty sure I wasn't crying just because it turned into an alternate history series.

Alternate history "What ifs" are difficult to pull off, and I think maybe the twist shouldn't have worked in this particular case because the series was so well-grounded in the time period, and it used foreshadowing and built momentum for the inevitable ending so thoroughly that I should have felt let down when history changed, but I didn't.  Instead, I felt a keen sense of loss because the alternate history the books ended on didn't happen in the real world, and I wish it had.  I look forward to rereading the whole series knowing the ending to see if that changes how I read as I go along.

Some books and series don't have much reread value once you know the end; others do.  Sometimes it's because the writing is so excellent, the ending didn't really matter that much.  Sometimes the characters are so great, you just want to spend time with them again.  Sometimes, though, you read because the momentum of the plot propels you toward the ending, and once you reach it, that's all.  Now you know what happened and can go on with your life.  In most western (genre) fiction, spoiling the ending means saying who dies or who did it in the beginning.  If you know that, why read the book?

I've heard and viewed and read alternate arguments about Japanese storytelling (novels, anime, manga).  Knowing what happens in the next episode or at the end of the book doesn't matter to them as much; it doesn't spoil things, necessarily.  How things lead up to it are equally if not more important.

So, any manga or anime you really liked reading/watching but will never read again because you know the end?  Any that have particularly great reread/rewatch value even if (maybe because) you know the end?