Need new Co - Op Games

I just started playing Don't Starve Together a while back, and while I'm playing alone, it definitely seems like it would be an awesome game for playing with friends. Some of the weird stuff in that game's definitely good for a laugh.

This is a great tool which can do exactly what you want - you can filter your library by tags and sort by metascore.

Whats with coop-games like Left 4 Dead I and II? Warhammer Vermintide or Space Hulk Deathwing? If you like Diablo 3 like games: Titan Quest? Sacred? There are also a lot of other games like this

Doom Troopers: Mutant Chronicles, Battletoads, Adventures of Batman and Robin, Streets of rage 1,2,3, Remake, Contra Hard Corps, Double Dragon Neon, Red Alert 3, Far Cry 5, Dying Light, Dead Island, Dead Space 3, Dead Rising 2, Resident Evil 5, Teenage Mutant Ninja Turtles: The Hyperstone Heist, Heroes of Might & Magic 3, Payday 2, Fortnite Battle Royale Duos mode, Lost World: Jurrasic Park. The Haunted, Hells Reach, Killing Floor, Left 4 Dead and 2, Portal 2, nothing else comes to mind coop wise.

This is coop with pretty good ratings: Looterkings

Divinity 1 and 2, Grim Dawn, Lego Games, Killing Floor, Portal 1 and 2, Dawn of War games!

Overcooked, but only local coop / mp! Preferable with joysticks.

Apart from seconding the Don't Starve Together recommendation above, here's a few more:

• Pit People is great and very entertaining, but only for two people.
• Guns of Icarus (Alliance or not) can be very hectic and enjoyable.
• E.Y.E. Divine Cybermancy is probably the most fun I've had playing coop. Fair warning though, the game is weird and has quite a few rough edges. Depending on your group it might not fit at all.

Duck Game, Lethal League, Rocket League, Tricky Towers, Ultimate Chicken Horse, Battleblock Theater, Castle Crashers, Crimsonland, Frog Climbers, Gang Beasts, Helldivers, Moonhunters, Move or Die, Screencheat, Broforce, and Gauntlet are online friendly co op games I have installed and play semi-regularly that I rather enjoy. I do see you have some of these already.

To narrow it down a bit, are you looking for competitive co op or cooperative co op? Online or local play?

Psychoapeman's suggestion is a great tool. I've used it to tag my library with games that are primarily co op (local) and online play, which makes it a lot easier if I have friends over or am looking specifically for something online with a friend.

I second the Lego games and add Guacamelee, Trine 2 and the Lara Croft isometric games.
And if you're looking for info, news and detailed co-op reviews on co-op games, I recommend
http://www.co-optimus.com/*

They are primarily interested in cooperative co-op games so you won't find vs games there unless it's a mode in a coop game

Orcs Must Die 2 is worth a look.

Kalimba - only local but one of the best co-op puzzle platformers, I had a blast with a friend.

The Trine games are a delight, though it's really best to think of the third game as the first in the series, given its comparative depth to the first two games. They're easily my top PC recommendation for co-op.
Of course, Starcraft 2 recently made all its basic features- including most of its co-op mode- free, so that's a (very) low-budget consideration. Likewise, Diablo fans should give Path of Exile a go- in some ways, it's a weak example of the Diablo-like genre, in other ways it has lots of depth that other games in the genre don't have, but most of all it's free, so it's easy to find out for oneself if it's appreciable.

I haven't played the Divinity: Original Sin games yet, but the original Divinity games were good fun, and the OS series seems to blow many gaming expectations out of the water. They're definitely my most anticipated co-op games.

Behemoth (Castle Crashers, Battleblock Theater, Pit People) has some solid co-op games, though the games are filled to the brim with potty humor, which is off-putting to many gamers. Ibb & Obb is a fun and challenging co-op puzzle-platformer. Saint's Row 3 and 4 are excellent if you want co-op GTA-styled FPS gameplay. Lara Croft and the Temple of Osiris is pretty much nothing but bugs and regrets, but Lara Croft and Guardian of Light is a lot of fun (though it has its share of bugs as well, but they're mostly amusing, minor ones).

I adore the Lego games, but they're exclusively couch co-op, without any online capabilities.
Portal 2 is good for co-op, playing much like the single player Portal experience, though it's perhaps a bit on the short end for total gameplay length (then again, the Trine games are fairly short as well). While Dead Space 3 has some weird bugs and weird design decisions that can frustrate an individual run, the overall experience is fairly good, and comparable in some ways to a Gears of War [which is also available on PC] co-op experience. The Left 4 Dead games are a bit clunky in places, but one of the better options for co-oping with more than two players (and still above-average when co-oping with two).

I didn't see anybody mention Splinter Cell Blacklist. It is a good two-player co-op stealth action game.

Shank 1,2, Resident Evil Revelations 2 (Online coop only on shadowplay), Resident Evil 5, Resident Evil 6 (forget about it), Trine 1-3, Divinity OS 1,2, Serious Sam, War in the North, Shadow Warrior 2, Saint Row, Aragami.

It's old(ish), but how about Borderlands?

https://www.lorenzostanco.com/lab/steam/
This for sorting by tags. It's great

Also

BROFORCE BROOOOO!
http://store.steampowered.com/app/274190/Broforce/

shank 2, lost castle, Rampage Knights, Lovers in a Dangerous Spacetime, JYDGE. Those are for local-coop game if you want some 4 player local that you can play versus friends for fun i have other game to suggest, trust me there is alot of local-coop game or just 4 player local game on steam, when alot of people think that the era of local gaming is dead, which is not true at all. ENJOY!

Here's another site you could try.
http://www.co-optimus.com/games.php

I'm an avid cooper myself and the game me and my mate have enjoyed the most are (in order of rough(playtime)) :
Borderlands Series, Civilization Series(Kinda RTS), Heroes of Might & Magic Series, Dying Light, Dead Island Series, Warhammer 40,000: Dawn of War II(RTS), Sins of a Solar Empire: Trinity(RTS), Portal 2, Trials Fusion (for competetive urges), Saints Row IV, Left 4 Dead Series, Grim Dawn, Serious Sam Series, The Incredible Adventures of Van Helsing, Magicka Series

That should be everything noteworthy ( 10h+ ).

Alright .. hope that helps broadening your horizon

edit
Also Splinter Cell Blacklist + Diablo 3 Reaper of Souls

I also would like to apologize for my lack of linking .. but I'm a lazy bastard ..

I've made a page trying to list any co-op game worth trying if you feel like going through the huge list.
http://store.steampowered.com/curator/29958364/

Personally I recommend Borderlands games, Torchlight 2, Saints Row games. It all depends on your taste for games.

A game I have been playing a lot coop with my brother is Lost Castle, I purchased that this winter sale when it was on sale, it is pretty fun coop again, but be warned it is or can be pretty difficult.

Played lots of local coop (splitscreen) games with my sister (on a projector) lately, here's what we enjoyed:

Broforce
Human Fall Flat
Goat Simulator
Cook, Serve, Delicious!
Trine (1,2,3)
FORCED
ibb&obb
Lego games (all of them! Favorites were LotR & Super Heroes)
Lara Croft and the Guardian of Light
Magicka
Monaco
Neon Chrome
Nex Machina
Never Alone
Portal 2
Unbox
Worms Revolution