Depends how old.

Overcooked/Overcooked 2 are great 4 player games with local coop

https://www.co-optimus.com/

This only covers games with a co-op mode, i.e. exclusively solo or competitive games are out of scope. It will let you filter by feature, player count, and platform. It's well worth having a browse.

I spend most of my family game time with 2 player co-op but some highlights that scale to more players are Rayman legends, Bonkies, and Sackboy's adventure

Jackbox games

Little Big Planet is fucking amazing, both the mini games and the story in multiplayer.

Ultimate chicken horse. You can play locally and with people online. Play it with my kids (11 and 8) all the time and they love it. Tetris connect and Spelunky 2 are fun as well.

Edit: the Overcooked games are fun couch co-op games too.

Rabbids is really fun. Most of the PlayLink games like knowledge is power, chimparty, frantics, that’s you, just deal with it, uno. All of the jackbox party games. We probably had the most fun with the murder mystery trivia one. Little big planet, gangbeasts, wobbly life, goat simulator.

Lovers in a dangerous spacetime (I think that's what it's called) is a pretty fun 2d co-op spaceship flying game.

Moving Out and Overcooked are hella fun.

There's Nickelodeon Kart Racers, which supports up to 4 player split screen

Super monkey ball banana mania apparently has about a dozen party games as it compiles content from the prev releases. Have played some of them on the GameCube - Monkey Target being a fave.

Ones I love: Sackboy, Overcooked All You Can Eat, and Ultimate Chicken Horse

Upcoming: Plateup! and Make Way

I've also heard good things about Tomb Raider Temple of Osiris

Tiny Tina's Wonderlands has local co-op up to 4 players.

Hidden in Plain Sight