The moment Nick hugs Kat after she's found out that her ex-lover dumped her because he was sleeping with her sister Amy. Sigh. You can almost feel how much Nick loves Kat and how he's trying to protect her with his hug.
The way Nick and Kat dance together at a pre-wedding dance lesson just makes your stomach churn for that kind of chemistry.
Plus this film has ALL my favorite songs in it.