Railway children (at the end). I also can't watch this without crying.
Guess How Much I love you, although fortunately the DC aren't keen on that one.
Dogger, at the sister's sweet gesture
Charlotte's Web
Heidi, when she goes back to her grandfather
Pollyanna, at various places
Little women
Anne of Green Gables, when Matthew died
Patchwork cat
The Selfish Giant
Peter Pan upset me very much when I read it as a child, so much so that I don't know if it would make my cry now because I haven't read it since, ditto 'The Little Mermaid'
I am a bit of a wuss, it isn't unusual for things to make me cry!