Not a movie, but when Simon punches Rossiu in Gurren Lagann. It was freaking incredible, if you're into over the top anime stuff. It looks stupid as hell out of context, but as the culmination of three quarters of a season, it was absolutely perfect.
Not just in that it was over the top (though it was) but as a narrative element and the way it played into the themes of the show, it literally could not have been better.
Long story short, the show is about human spirit being capable of literally anything, and goes to outrageous extremes to demonstrate it. About 10-13 episodes prior, Simon and his mentor had recently developed an asymmetrical relationship when Simon begins to view his mentor as a rival who was winning, leading to self-doubt, leading to losing the battle. The Mentor then straightens him out with an over the top punch. Simon and Rossiu's relationship in the latter half of the series develops in exactly the same way, but with much higher stakes and a lot more complex, so Simon straightens him out in kind. It's a cyclical narrative structure that seems to prove the bad guy's point about the human spirit, but... GAAAAAAH I WISH I HAD TIME TO GUSH THIS SHOW IS SO FREAKING GOOD.