9. The Binders
Despite the fact that Captain Holt is a man who paints rocks for fun, he still manages to be one of the most healthy representations of a gay man that has possibly ever graced television. He's a fully fleshed out character, who isn't just killed off for drama, and while his sexuality is not his defining trait, the show also doesn't shy away from exploring how being a gay black cop in the '80s greatly affected his life and career.
This is why the rainbow coloured binders behind Holt in his office aren't a huge plot twist, but rather a cherry on top of the televised cake. It's not revealing some great secret - after all, Holt tells us he has a husband in the very first episode of the entire show - but it does reveal a sense of pride that is warming to see.
It's also worth note that Gina is also shown with these binders before we learn she's bisexual. Again, this also isn't a ground-breaking revelation, but rather a reveal that fleshes out one of the characters a little more, while also providing some much appreciated representation.