Xonotic

Xonotic is a free and open source first (or third, if you want) person shooter true to the Quake gold standards with some pretty unique weapons with dual attack mods and a excellent modding / mapping ecosystem. The game has a unhinged nature, which is EXACTLY what I like. Community is tiny but great (hello DarkBlue!)

Splitgate

Splitgate is basically halo with portals. That's it. Just adds another dimension to shooters. I like how fast paced it is, and the community is pretty chill (but a little too small for a game like this)

Space Engineers

SE is a sandbox. It can only be described as 2B2T in space. Everything goes.