this is an odd one but when I'm watching a movie with my son and he hasn't seen it before (Like me he loves Sci-Fi and Fantasy movies. Seeing him get overexcited about a movie and that makes me excited too.
We just finished watching Judge Dredd (Yes I know it is flawed, unfaithful and terrible) and he loved it and was getting excited watching it as a movie not an interpretation of a Comic character.
I went awwww and have had a smile on my face ever since.