TempelOS?

plan9

NixOS is the new Arch. I'm surprised nobody here has said they use it yet.

Write your own OS running on RISC-V.

Haiku.

If you're not on TempleOS, you were never really serious about feeling superior

GNU Guix with the GNU Hurd kernel? A full GNU/GNU system, or GNU + GNU.

There's always LFS.

But if you really wanna bail on tux, Haiku, Plan 9, or ReactOs

Abandon technology and become a farmer.

Run exclusively self made programs

Need a calculator? Program one and compile it

Well, within reason

Plan9, then you can smugly say Unix systems are sooo legacy.

Haiku OS

Open source Windows obviously. https://reactos.org/

All these recent Windows to Linux converts, whining about how Linux should be more like Windows, should be going to ReactOS. They want open source Windows, not open source Unix.

Back to LFS.

Haiku. It's a reimplementation of BeOS.

Alternatively, you could use ReactOS and make it look as windows-like as possible, and then go and post on Windows support forums with solutions to problems that work for ReactOS but not for actual Windows, and then play dumb while calling them dumb when it doesn't work for them.

I use arch btw.

You get an ARM or RISCV machine to run Linux on obviously. Then you shit on the plebs with their legacy systems.
You also need PostmarketOS on your phone of course.

Obviously, you need to get BSD on a computer without any proprietary firmware.

https://www.ponyos.org/

Everyone saying nixos the next arch but we are all traumatized so we dont even recommend it /hj. But actually dont use it, youre gonna give up or spend hundreds of hours crafting the perfect deployable system which youre never gonna deploy on anything other than your single laptop that has nixos.

None, go outside and absorb sunlight

Make your own, coward. No distro so niche as one that has half a user because it's hardly usable.

GNU Hurd?

Now you have to move on to obscure open source hardware. Linux phone and/or a RISC-V computer

Just a pure Rust computer. No operating system, just Rust.

There is two other paths: 

• Gnu herd
• Plan9