Well, I would go with Swat4, I have a lot of very good memories from lan party playin this game with 3 other friends (that was eons ago ahah)

Thanks for this nice contest and cheers from France

FEAR 3 had a unique co-op mode. One plays as the good guy with standard FPS controls, the other plays as a psychotic phantom vampire. Great for Halloween.

I know many people will recommend this, but I think the best game coop game is STARDEW VALLEY.
I have play a lot of coop games with my friends before, like Super Contra, Streets of Rage, Sengoku 3, Tower of Doom, Overcooked, Cuphead, Left 4 Dead, Portal 2, Broforce, Sven Co-Op, just to name a few, but Stardew Valley give me one thing all those game didn't... it give me peace. After a long and stressful day at work, nothing is better than arrive to my girlfriend house and play a litter coop session with her daughter, she always wait for me, we play a little a feel like if you recharge you batteries. The game teaches you what sometimes to put down your weapons and enjoy daily tasks, it's all about take it your time, you can go to fishing, take care of your harvest, your animals, travel for the town, build your farm, progress, spend time with friends, discover new things, explore the mines, have an incredible adventure, enjoy the holidays, go to a birthday, try a new recipe, know new people and see the seasons come and go, now imagine all those things and more, with a partner, collaborating and creating together, enjoying together.
Another good thing about Stardew Valley is that is a game for everyone, you can play with your child, your friend, your wife, your mom or even your grandma, the game is simple to understand and more easy to play, everyone can enjoy a beautiful moment.
Other point is the fact that the game could run on a potato, with a beautiful pixel art, you know even your old battle horse will run it without problems.
The soundtrack is great too, very relaxing and you can use it for a yoga class.
So yes, that is why I recommend Stardew Valley over other great titles, take your time people and enjoy life and company, more in these hasty times that we live!

Well this is a very confusing description.

What is a "creative" recommendation of a co-op game even supposed to mean?

Are you expecting recommendations of actual co-op games? Imaginary co-op games? Hacks to make solo or competitive games playable in a co-op fashion?

What is a unique entry? If I post a suggestion and someone else posts the same suggestion later, then we're both disqualified? In which case you're NOT looking for actual good co-op games, because chances are high that people will recommend them.

Honestly, I have no idea what you're looking for here.

Bubble bobble.
How could in not be. If that tune is not earwormed in my head the rest of the day I'll be very surprised.

Best Coop Game Exp, simple - Synthetik. Enjoy :) When my wife was pregnant we had some great time with Hammerwatch too.

Super Mario Bros 3

It's the game that got me and my brother into games, I can't think of better coop than that :)

How about Sacrifice? It's fast-paced, whacky, and simple-yet-deep. I like the feel of an RTS with a third-person perspective camera. It has a whole lot going on on the map, and this camera perspective is great for capturing the sense of chaos, so it's perfect for broadcasting.

If you have a really long time to play, I'd say Divinity:OS (1 or 2) or, if you have the balls for it, Outward.

Other than that, I'd like for you to finally fix the multiplayer on the GOG version of Spellforce 3, so maybe playing that will give you an incentive.

Gotta go with Guacamelee

The original Icewind Dale games.

Amazing soundtrack and atmosphere, and more freedom than their more acclaimed counterparts (no recruitable NPCs like Baldur's Gate, less directly personal storyline, etc.) make these an absolute gem to play in (preferably local/lan based) coop. Some of the most fun experiences I've had actually roleplaying in an RPG with other players.

Magicka is the most fun I ever had playing co op

Best Co-op Game?

Wow... That's actually a tough one because as "good old games" go, the Double Dragon and Contra franchises are still excellent co-op games after all these years. It is impossibe to choose just one of them.

I guess I'd have to go with Contra simply because it has all the tropes of Alien, Predator and Terminator all wrapped up into one epic package best enjoyed with two players.

Ikari Warriors

splinter cell chaos theory
venom. codename: outbreak

I just must highly recommend Dying Light! My brother and I are playing it for the second time right now and it is so much fun.

We have been playing for about three weeks, still haven't completed the main story and have only popped over to "The Following" map to look around for a few minutes, so we still have a ton of content left.

Honestly, Dying Light is the most amazing co-op experience I've had and my brother and I have been co-opping games since 1998, so we have tried a LOT of games.

The movement system in Dying Light feels amazing and it is hilarious when you are running around the city, chopping zombies down and suddenly see your co-op partner go flying past you with their grappling hook. I can't tell you how many times I've had to stop playing for a minute just to catch my breath from laughing so much because of some ridiculous thing that happened in the game.

The loot system is incredibly satisfying too. If you and your friend decide you aren't in the mood to do missions, you can spend hours just running around picking locks on cars/vans/chests for loot, crafting and upgrading weapons, searching for collectibles (zombie statues, flags, journals, etc), trying to find new blueprints, unique weapons and easter eggs, hunting the game's more difficult enemies to get crafting materials for the best weapon blueprints, etc.

There is just so much to do in the game and there is something about it that just makes it never get old. No matter how many alcohols I have (over 4000 right now), no matter how many locked chests I've opened, I can't help but be excited every time I stumble across another lock to pick or huge mob of zombies to kill because you never know what you'll get next.

All this with a friend added in is just next-level fun to me. The way Dying Light's co-op works is pretty awesome too. You and your friend can play together for a few hours, then you can each play your own save solo until you're ready to meet up again the next day, and you both keep all the items and stuff you earned while playing solo.