Can't go wrong with either.
Assassins Creed Origins or Middle Earth Shadow of War? Can't decide weather i want to start my own army and have mad beefs with orcs or explore ancient Egypt and sh*t..
Shadow of War is a great sequel. You'll feel right at home when you played the first game. It doesn't do anything outside the box, it simply adds a lot of new stuff to the original formula. They took the Nemesis system to the next level. You'll meet countless new orc personalities and forging your own army has never been so fun before.
Origins is a reboot of the franchise, many things are new to the series and a few things are scrapped. Egypt takes the cake here, it is beautiful, huge and diverse. If you want to explore a new RPG world, follow the best AC storyline since Ezio (if not better) and are curious about the combat system, this game is worth playing. It feels like a new RPG world like Skyrim or Fallout, where you can spend hours and hours exploring, something an AC game never made me feel before.
It's a tough one. I'm playing through both games but if I had to choose one, it would be AC Origins. Shadow of War can be a grind sometimes and the maps aren't impressive enough. It's still a great game and I simply prefer Origins out of personal taste.