What are some good on-line co-op games?

What games do you enjoy playing in on-line co-op? From FPS to sports games what have you really enjoyed? I'm currently playing Golf with Friends and enjoying the simple, sometimes relaxing, sometimes frustrating nature of the game.

  • Lately, the co-op games I'm playing are Gunfire Reborn, Inside the Backrooms, and Gang Beast. 

  • Some really nice choices listed in this thread!

  • Elden RIng has multiplayer I've enjoyed immensely. It allows 3-4 to play at a time & setting a password just for friends. 

  • I've been enjoying viking saga for more fast paced gaming and Stardew valley for more relaxing time.

  • These type of games are great for building leadership and team building skills!

  • I've enjoyed most of the Battlefield games online... But as for simple ones, I don't know... you're probably best off with Chess or Go. 

  • Left 4 Dead 2 can be fun and a little wild.

  • I've recently started Destiny 2.  I really like how you can invite people to your fireteam at any point in a mission, rather than only at the start like in games like Warframe.

  • I left the genres broad to see all the  interesting co-op games that are out there. Thanks for the suggestion of Ibb And Obb. Looks like a fun challenge.