Honestly, I'm very picky and it has to be something really powerful to get me to cry or be surprised and shocked.
The Goofy scene. When Goofy got KERSCUFFLED on the head with that boulder and it seemed like he was dead.
It was the reactions that really got to me. I was emotional over that because I LOVE Disney. Always did. Even WAAAAAY before KH came out.
Then, both scenes where Kairi hugs Sora, I wasn't really shocked, something was supposed to happen between them.
When I found out 'Xehanort' was actually Riku... that practically knockewd me off my chair. (It almost did, actually)