I love love love love love me a good grump x sunshine. BONUS points if it's reverse where the guy is a total golden retriever and the woman is a black cat. I just finished King of Sloth, which totally gave off that vibe.
The Littlest Library made is the one I've most recently read with this trope I think. I loved it, but I should note while their is a romance within the book it is not the main plot. I wouldn't label it a romance. It was however a wonderful read that made me tear up multiple times with the good tears and was extremely cozy. I recommend it!
Besides fake dating/marriage, grumpy/sunshine is my favorite trope. One I loved recently that isn’t fully romance, but more fantasy romance is “Assistant to the Villain”, by Hannah Nicole Maehrer.
The Simple Wild. Oh I loved that one. The parking lot scene. If you know you know. Didn’t know how the author was going to redeem him after that. The Fine Print was a good grumpy/sunshine one.