All distributions of free, open-source and user-empowering software like Linux are great and deserve recognition. Whether it's simple, new user-friendly distros like Linux Mint that make the transition process from proprietary garbage like Windows as easy as possible or advanced distros that are meant for power users like Gentoo, Arch or Void Linux. But these specifically deserve more recognition in my opinion:
Gentoo. People hate it for being hard to install or because it's source based, but it allows you to customize everything, including build options for programs etc. It empowers users and teaches them a little about how their system works. Gentoo doesn't tell the user what to do, the user is in full control of their system. ChromeOS is based on it, because it offers infinite flexibility and customizability.
Also, Tails OS. It's what keeps many oppressed journalists and activists anonymous and secure, and it's what Edward Snowden used to inform the public about the horrible things going on at the NSA. The same goes for Qubes OS and Whonix.
I don’t get the sense that people hate Gentoo, I think it’s mostly just people joking about it. That said gentoo is really cool and doesn’t always get the respect it deserves, but I think most people who actually follow through with it have some appreciation for it!