This just hit me. The guy has played a Nathan Drake-y character in some of his movies, he looks a little bit like him and he's starting to be really popular. I think he'd be a good choice. Sony would satisfy fans by casting a good actor for the role, and they'd have the star-power to attract a mass audience. It's true that Nathan Fillion is Nathan Drake, but there's just one thing that would prevent me from hiring the guy if I was producing the movie: he's too old for the part. Sure, he looks attractive and doesn't have grey hair yet, but what if Sony wants to do multiple films? What happens in 6 or 7 years, when he'll be 50 years old?
That's why my wish list has only two dudes now: either Chris Evans or Bradley Cooper. I think both would make a terrific Nathan Drake.