Coop game recommendations

Keep Talking and Nobody Explodes is the perfect asymmetrical co-op game. Most games, you can still play co-op without needing to say a word to each other, but with KTaNE, you NEED to communicate. One person gets a bomb to defuse, and one person gets a manual on how to defuse bombs, but neither person can look at the other's screen. The defuser needs to explain what they see, and the expert (the person with the manual) has to figure stuff out and tell the defuser what to do. If this sounds interesting to you, I'd say check it out.

Since one person just gets a manual, you don't even "need" more than one copy of the game. If you can share a computer, you can just take turns. If you can't but still want to play, then just have the person who owns the game as the defuser the entire time.

Castle crashers/Lost castle(Can say castle crashers is a very entertaining game)
Borderlands 2(youll never get bored of the same thing)
Portal 2(quite a nice coop)
A way out(its on Origin, and i think youll get bored after you play it once)
Magicka(a bit funny at the start)
Don't starve together(cant comment on it since i ever played it)
Killing floor/L4D2 (but its better with a few more ppl, even though 2 does suffice. I also prefered KF1 over KF2 due to the goofiness and voice lines and nice grind xD. But it would much more fun with 6 ppl in a server than just 2)

All Lego games, Lovers in a Dangerous Space Time, Risk of Rain, Portal 2 (a ton of mods, almost infinite), Broforce, Left 4 Dead 2 (it has the campaign from 1 and a ton of mods), Astroneer, Saints Row 3, Don't Starve Together, Lara Croft and the Guardian of Light, Lara Croft and the Temple of Osiris, Gauntlet, and Stardew Valley is highly recommended. I played with former lovers and friends, it was always fun.

Few games me and my friend enjoy
Rocketbirds
Doorkickers Action Squad
Helldivers
Spintires
Brawlhalla 2v2

Here is a group which might be exactly what you are looking for.

Overcooked and Overcooked 2:)

Styx: Shards of Darkness is a great coop stealth game.

Trine games!

Terraria
Borderlands
Path of Exile
Grim Dawn
Risk of Rain
Helldivers
Divinity: Original Sin 1+2

I'm also looking for games, although Local Co-Op only. A game that can be played using controllers (aka no shooters, really) Any good recommendations?

My friend and I really enjoyed Shadow Puppeteer and Never Alone.
We also tried Trine but I find the platforming parts frustrating, I'm really bad at timing my jumps. I'll just post a list of games in my local co-op folder, maybe you find something interesting, can't comment on most cause I haven't tried them.

Battle Chef Brigade
Borderlands
Brawlhalla
The Escapists 2
Guacamelee
How to Survive
Hyper Light Drifter
It came from space, and ate our brains
LEGO games, I think all of them have local co-op
Magicka - funny game but I found it much harder to play with a controller.
Octodad
Overcooked - it's waaay too hard for just two players, even three. If you have enough controllers and people to play with I'd recommend it.
Paperbound
Party of Sin
Pid
Small World 2
Soul Searching
The Yawhg

Me and my bf are in a long distance relationship, so co-op games are pretty much our thing.

We had a great time with Orcs Must Die 2, Torchlight 2, Moon Hunters (local mode is better, tho), Don't Starve Together, Starbound... Currently we're playing Path of Exile together and just bought Hacktag. The first We Were Here is free on Steam and it's pretty good.

Our local co-op options are Overcooked, Lost Castle, Lovers in a Dangerous Spacetime and Swords of Ditto. Roguemance is a cute little hidden gem that may be worth a look, but the gameplay may be a little too quirky for some.

I really loved playing "A Way Out" with my husband, because I felt like this was one of the few games where you don't play against or alongside each other, but you really play together as a team. And the story is lovely :)
I can also recommend "Borderlands 2", "Portal 2" and "About Love, Hate And The Other Ones"

Zombie Army Trilogy was a fun game shooter for SP or up to 4 player co-op.
Various different characters, even Left 4 Dead ones.

A lot that came to mind have already been mentioned. Terraria, Trine (whole series has co-op), Grim Dawn, Divinity Original Sin (1 and 2), Saints Row the Third, Portal 2.

Golf it! (Early Access) - https://store.steampowered.com/app/571740/
Monster Prom - https://store.steampowered.com/app/743450/
Plagued INC Evolved - https://store.steampowered.com/app/246620/
Saints Row IV - https://store.steampowered.com/app/206420/
Saints Row Gat Out Of Hell - https://store.steampowered.com/app/301910/
Staxel - https://store.steampowered.com/app/405710/
Tiny Brains - https://store.steampowered.com/app/253690/

LEGO

FIGHT N RAGE.