I sort of laughed when Sirius died. I know its wrong. But I thought he had disapparated or something. But then when I saw Harry shouting and Lupin holding him back and heard the sad music I broke into tears.
I'm generally a very weird person, I show emotions really badly. xD
I sometimes even shout at the TV so...yeah.
EDIT:
I forgot to say my thoughts on Dumbledore!
I think I will cry when Dumbledore dies. If its like its been wrote in the book I'll probably cry through the rest of the movie. xD