I will go to my grave, the final scene of Moonstruck in the kitchen. I would post it, but it is too long. One of the best scenes in movie history. All the way when Cher walks in from spending the night with her fiancés brother to the end.
Might be the best scene of the whole movie. I think it was improvised in one take and if so, Catherine O'hara deserved an Oscar for keeping it together.