A Way Out is really fun to play with 1 friend, Pummel Party is also good if you have a group
Uhhh in my experience it was COD Mw3. Now maybe some strategy game like Total war or coh2 ,idk, my friends only play fps
Left 4 dead
police stories, door kickers, blood and bacon, dont starve together
For the King is a lot of fun. Games like Rust and 7DTD can be fun for a bit too. The Forest is a solid Co-Op Survival game. Killing Floor 2 is less straight up Co-Op story but is a lot of fun as a FPS Co-Op wave based shooter.
Without some clarifications on what Genre I'm just kind of spit balling fun games I've played Co-Op atm.
If you liked A Way Out another nice 2player Co-Op is the "We Were Here" Series kind of a Co-Op puzzle exploration thing.
We were here, we were here too, we were here together
Serious sam 3, Sniper elite 3/4 , Resident evil 5
Zombie Army Trilogy, Killing Floor 2, Insurgency (coop actually really good too)
other than what's recommended already, starcraft 2 co-op is pretty chill not the biggest variety tho
GTFO, Dead By Daylight, Battleblock Theatre, Man of Medan (If you're into horror), Resident Evil 5, Monster Hunter World, A Way Out, Terraria, Dark Souls Series, Castle Crashers, Earthfall, Painkiller, CoD Zombies, Killing Floor 2, PAYDAY 2, Zombie Army Trilogy, Far Cry 5, RAID: World War 2, Escape From Tarkov or look for an emulator like dolphin and configure it for online coop then you can play things like super mario galaxy, mario kart, mario party etc. Pokemon Firered coop modded is also pretty fun. Or Banjo-Kazooie via online PJ64 with the Devil Bottles mod or Super Mario 64 Coop Mod. All things me and a few mates did back in the day.