There should be a law against not changing your default wallpaper if you're a hacker! You really spend hours and hours staring at a screen with that nasty bruise looking default Ubutnu wallpaper? Yuck! I'll be keeping this updated for you guys. I try to find ones that are hard to find too so these should be somewhat rare.

Deadcool
Dead-cool

Space ship
Space ship

Saw this on MKHD
Saw this on MKHDs videos once

Everest
Cool Everest Minimal

Kali
Kali White