Some that I havent heard but love are Pandemic and Spirit island.

And as a hidden gem: Heroes of Tenefyre and sprawlopolis. Heroes is a deckbuilder dungeon crawler where the new cards in your deck are the monsters you slay. Sprawlopolis is a city builder the size of a small wallet, which you can easily take with you. There are 3 challenges out if 18 which decide how the game will play, which asks for different tactics every time.

I love co-op games. A few of my favorites (in no particular order) are:

Fallout (w/ Atomic Bonds expansion of course)
The Crew (either version)
Black Orchestra
Stars of Akarios
Forbidden Desert
Gloomhaven
Mysterium
Arkham Horror LCG
Spirit Island

Honorable mention for some semi-co-ops:
Fury of Dracula
Specter Ops
Dead of Winter

The Captain Is Dead is underrated in my opinion - the theme is essentially the end of an episode of Star Trek or any other sci-fi show really but the main characters have unexpectedly died and it's down to you to scramble and try and fix everything before it all ends badly...

It's hard to win but a lot of fun to play!

Frosthaven/Gloomhaven. They're co-op, but all of the hidden information stuff stop other players from influencing your turns too much.

Absolutely wonderful games!

Love, love, love Burgle Bros 1 and 2.

We have also been playing lots of Hanabi lately and having a blast (pun intended)

Easily Spirit Island. Huge replayability, a wide range of difficulties, and impossible to quarterback for mortals

Spirit Island is probably our biggest mainstay at the moment. One of our group has most of the content and I'm still only about halfway through playing every spirit we have. The replayability is just amazing and the pacing is beautiful, hitting you hard in the early game and then slowly you turn the tide. Not to mention some of the spirits are just so doggamn satisfying to play.

We're also pretty big into Aeon's End. I completely hated this game in the beginning because I couldn't see how you could possibly win. Once it clicked and we began to get better, it became a lot more satisfying to play.

We also played through and enjoyed all Legends of Andor, all Pandemic Legacy, Mechs vs Minions and Gloomhaven.

Zombicide is one of my favorites. It's an rpg, cooperative board game that puts you against zombies while trying to complete missions. The various base games cover different time periods from midieval to present to scifi future. Each one tweaks the rules slightly to work better with the characters and environment

I like coop campaign games, some of those I liked most are: LOTR journeys in the middle earth, descent leyends of the dark and gloomhaven. I strognly recommend Gloomhaven Jaws of the Lion. Not the best, but very good and you will get a lot of value for the price, as all these are on the expensive side. Zombiecide is good and a bit lighter. Apart from those, I'm playing marvel champions now, which is a coop card game, great for two, a bit too long with more players.

My husband and I really like Wonderbook. It's a campaign game with several chapters. The theming is a bit childlike sometimes but the mechanics are fun.

Dungeon Fighter is a very silly coop game that might appeal to people that don't like board games normally. You're a group of adventurers and have to move through a dungeon. You roll the dice on a big bullseye board. The twist is that all abilities or traps etc. are in the form of modifying how you roll your dice. So you might have to roll the dice from below the table, or while jumping etc.

Here's a fun one I haven't seen mentioned: Castle Panic. You have to work together to save your castle from rampaging orcs and goblins

I don't see it mentioned, so: 2p Onirim is an interesting low cognitive game you can play with your partner before going to bed. You are in a common dream and both need to beat the game without talking, simply by giving hints. Playing with a low light is cool.

I wouldn't say it's my favorite co-op game, but still, it's easy to pick.

The crew 1 and 2 (fast paced card game)

Magic maze (real time mess, very funny, play with the extension only (the base game is super repeatitive after 3 plays))

Hanabi (logic and memory card game)

Gloomhaven (heavy rpg)

for sure I love flash point. I think it might be one of the most commonly played games I have.

I need more expansions for it though I've only got 2nd story

I love Gloomhaven. It's cooperative, but still offers some competitive gameplay elements.

EDIT: my submission is now the deep rock galactic board game. Heaps of fun and faithfully adapts the video game!

Shared 1st place:
Magic Maze
Pandemic: Fall of Rome

Shared 3rd place:
So Clover!
The Shipwreck Arcana
Top Ten

lightweight:

• forbidden games (Island desert sky)
• flashpoint
• castle panic
• escape the curse of the temple
• magic maze
• hinabi

medium weight:

• pandemics
• stuffed fables
• zombicide
• legendary predator
• Sherlock Holmes consulting detective
• the grizzled
• mysterium

heavy weight:

• Arkham horror the living card game
• Lord of the rings journeys in Middle Earth
• Arkham horror third edition
• mansions of madness
• Eldritch horror
• Spirit Island
• Robinson Crusoe

Absolutely love to play Dorfromantik with my kid, it even has campaign mechanics.

How is it even possible that no-one has mentioned the best coop/semi-coop in existence yet? NEMESIS.