The co-op game we've played together most is Left 4 Dead 2. It gets a little repetitive for me after a while, but it's still fun taking on zombies together.

Really fun coop shooter, your experience varies based on the character you play +weapon customisation. Downside is that you may have to replay sections, if you play with a lot of different people.

This game has a lot of silly fun packed in it, but it can become challenging!

This is a very interesting game that fuses the zombie genre with parkour. Guns are rare, so if you prefer shooters, you won't like this. The skill trees are actually impactful. Scary and lots of fun ~

You definitely have to be able to multitask/quickly switch tasks with this game. I played it with Imo and it wasn't for him, but I like this kind of challenge.

Levaritie, Imo and I have played this together. The game can get quite hard, but it has enough difficulty variation to be fun for every skill level. It can get hectic and nerve-wracking -in a good way

A very fun, but short top down shooter coop game that we played with some people from here. It's simple, no learning curve and very tactical. The aesthetics are amazing.