The Stuffy or Buttoned-Up Hero

I recently read two books that featured heroes who start off as stuffy and might even come across as judgmental: Her Best Worst Mistake by Sarah Mayberry (contemporary), and What a Gentleman Wants by Caroline Linden (historical).

Both are great books, so do check them out! Here's a link to the Dear Author review for the Sarah Mayberry book, which is where I first read about Her Best Worst Mistake.

Getting back to the heroes - as the stories continued, I, along with the heroine, began to see the person behind the stuffy mask, and each hero turned out to be really heroic - a truly good guy, someone the heroine can rely on through anything and everything. 

This is a trope I really love in romances. Do you? Are there any books you'd recommend that feature this kind of a hero?