Favorite grumpy girl + sunshine boy movie couples?

I am shocked I never heard of this trope before, but it is ever-present in some of my favorite movies.

To explain, in case you also hadn't heard of it: the grump girl + sunshine boy trope follows a courtship between a couple in which a sweet man wins over a woman who has lived a life of cynicism. Some examples: CeCe and Schmidt in New Girl, Kat and Patrick in 10 Things I Hate About You, Andy and April in Parks and Rec, Andrew and Margaret in The Proposal, and David and Patrick in Schitt's Creek (it also works for same-sex couples)!

Do you have a favorite that fits the trope? Even an unexpected favorite (like, Katniss and Peeta in Hunger Games still counts!)? And do you think this exists in real-life too? Does cynicism match with sweet?