Regarding the "Trying to prepare in advance" part. Download a complete SNES Rom collection from archive.org and an installer for SNES9x. The collections are around 1GB and include hundreds of games. Lots of them with Co-Op or two player modes.

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

Castle Crashers It Takes Two Contra Gears of War Halo Untitled Goose Game

If you are going to emulate then go for the Sega Dreamcast!

Virtua Tennis Power Stone 1&2 Toy Commander Quake Gauntlet Legends San Francisco Rush 2049 ChuChu Rocket Soul Calibur

Vampire Survivors couch co-op (2-4 players) is insanely fun. What's even crazier is that they will soon come with an update for online co-op

My all time favorite co-op games are: Helldivers 2, Vermintide 2 and Deep Rock Galactic. They are very much online games tough.

For offline local co-op my picks would be: the entire Trine series, Streets of Rage 4, Earth Defense Force 5 and Renegade Ops.

I have three recommendations.

Split Fiction is a master class in game design. The split screen is so integrated into the experience that even online multiplayer is in split screen. The screens are a part of the story.

The gameplay is constantly changing to the point that discovering new mechanics becomes the gameplay loop.

The level designs are so clever that you'll have several moments that feel scripted but were actually just inevitable because of how we play games.

To give a snapshot of the experience: there was one scene where my character was driving a motorcycle along the sides of skyscrapers, doing the craziest stunts imaginable, and my wife's character was sitting on the back frantically trying to solve a series of CAPTCHAs on her phone. She was so focused on keeping a steady hand that she barely noticed the death-defying stunts happening literally out of the corner of her eye.

By the end of it I was like, "Did you see that??" and it turns out she did not. It was absurd and hilarious, and it's the kind of storytelling that only works in a video game.

My current obsession is UFO 50, which is a collection of 50 "retro" games. In real life they're all new, but the story of the game is that they're from a company from the 80s called UFOsoft, and then there's a dark meta narrative hidden in the background.

Which is all just a framing device for 50 games, most of which are good, some of which are amazing, and half of which are couch co-op multiplayer. It's like exploring the Switch's retro NES collection for hidden gems, except there's a lot more gems.

There are beat 'em ups, obscure sports games, some platformers, tactics games, a little bit of everything.

I've enlisted my wife to help me, because a lot of these games are just begging to be grinded out in co-op.

I got the game when I saw someone describe it as "a master class in game design", and I thought, "that's the phrase I've just been using to describe Split Fiction."

And finally, I recommend Lovers in a Dangerous Spacetime, because that's the multiplayer game I've been recommending for almost ten years.

You each play as adorable creatures in an adorable space ship that you customize as you go. The ship has several stations that need to be manned, including the captain's seat, navigation, a directional shield, and multiple weapons.

But you each can only man one station at a time. So if you need to stay on the shield but a new enemy is approaching from the other side, then that means the captain is going to have to jump on a weapon and leave the ship adrift.

You may have arguments over which type of weapons to add to your ship or over who's better at piloting which kind of engine. Or maybe you'll work together in perfect harmony, relying on each other's strengths and covering each other's weaknesses as you adapt to every new challenge. Both ways are fun.

Also great for up to 4 players.

My girlfriend and I play (mostly local) co-op sometimes. Some games that we enjoyed so far were (local unless otherwise indicated):

• Divinity: Original Sin 2
• Baldur's Gate 3
• Portal 2
• Diablo 3
• It Takes Two
• A Way Out
• Minecraft (online)
• Stardew Valley (online, may also work locally now)

My wife and I beat Unravel Two.

That was a fun little game.

Reminds me of playing Doom 2 co-op with my brother. I wanted to just play the game but he'd end up shooting me instead until I cried.

Good times.

In contrast to the party games everyone else is listing, I'm gonna say Divinity: Original Sin 1 and 2. They're more long haul affairs, but still make for great lan gaming.

Something I would quite like are coop games that don't require anyone else to buy the game. Keep talking and nobody explodes works well for that, can have more people too as most of it is communication rather than control inputs but only 1 person is holding the mouse/controller.

I have a steam controller and can stream my PC to the TV with steam link. Apparently some games can be played with multiple controllers but I don't have any others and they don't make steam controllers any more. Not even sure how well that even works on Linux as it is something I have never tried.

If you're taking about couch co-op games these are pretty great:

• Teenage Mutant Ninja Turtles: Shredder's Revenge (6p)

• Boomerang-fu (6p)

• Overcooked (4p)

do we include arcade games? because the xmen and golden axe2 were big ones to play with a friend using only one quarter. The old baldurs gate for consoles from the aughts was a great two player co-op.

Some games I enjoy a lot are:

• Advanced Wars 2 (GBA)
• My Little Universe (PC)
• Overcooked (PC)
• Out of Space (PC)
• Unrailed (PC)
• Biped (PC)
• Tom Clancy's Splinter Cell: Chaos Theory (PS2)
• Trine Series (1-5) (PC)
• It Takes Two (PC)
• Ratchet and Clank: Deadlocked/Gladiator (PS2)

Borderlands. The first one. The game is amazing by yourself and slightly better with friends. It's not meant to be worse either way. It's just a lot of fun.

The later BL games were made the same way, but I haven't found any of the sequels (/"Pre-Sequel") to be as engaging as the original. They are bigger and more ambitious, though, with BL2 being a fan favorite. I just really like the Soldier (Roland) from the first game. The other games don't have a character I like playing as much as him, so I'd rather join the original rather than settle for a lesser character.

Actually, the best co-op game is Brothers: A Tale of Two Sons. It's played with your left hand and your right hand. I'm being a bit of a smartass, but technically it does qualify as co-op because two characters on the screen are being independently controlled and they must work together. But it is specifically designed to be played by one person. Your dominant hand should control the older brother, with the analog stick moving him and either trigger doing the action, whatever that may be (it's basically a one-button game, plus the stick). Your other hand controls the younger brother, same thing. So naturally the older brother runs straight and does what you expect but the little brother tends to stumble and waver. All intentional. Also, don't bother with the remake. It breaks a few things and honestly doesn't look much better. Different art style, not better. Just play the original. You can get it on GOG on sale all the time for like $2-3. Also, it'll take ~4 hours to complete and you'll probably never want to play it again (but recommend it to everyone). I actually bought the remake (mistake) and had my wife play it. For the hell of it, I speed ran both of them (this was on Xbox) for the achievements. Then I did the same on the original. Interestingly, you do not have to complete the game to get all the achievements! You don't even have to complete the final fight, or do the climactic scene before the final fight. Before you're even aware the climactic scene is coming, you sit on a bench and blip, there's the last achievement, if you're doing an Achievement% run, that's when you call time. (I'm not a competitive speed runner. I just did the runs to pop the achievements before uninstalling them.)

The Neo Geo Metal Slug games were extremely fun to play side by side with a friend. Just note Metal Slug 2 has lag problems due to the engine used, but it was later ported to MS3's engine as Metal Slug X.

Also, most versions of the games on PC come with the ROMs, if you'd rather use your own emulator.

Another set of games we also enjoyed a lot were the River City Girls games. Just had to use health cheats on the SNES game repurposed because it was getting too hard for the time we had. "<.<

My two are cult of the lamb (local/steam stream) and kingdom two crowns (local/steam stream/online)

For playing with my kid I got:

• Untitled Goose Game
• Pizza Possum
• Stardew Valley
• Shift Happens

These are all couch co-op for us.

A lot of good stuff in the comments but one gem that kept our entire family giggling for a long time is No heroes here. Stressful co-op in the style of overcooked but platforming and about cannons. I noticed there's a sequel but I'm worried any the 3D implementation.

https://store.steampowered.com/app/696140/No_Heroes_Here/

Crawl - technically pvp, arcade game Overcooked - try to manage a kitchen together Duck Game - completely pvp, ducks with guns, very fun

This is an older pull, but the Army of Two series was a ton of fun. Coop third person shooters with no more plot than your average action movie. It's great, lol

magicka 1 and 2 has couch and/or online coop, it's challenging, chaotic fun, with some pretty funny jokes
if you get into emulation, cooptimus hides older platforms under "classic", but it has another dropdown to filter them more precisely

Contra (NES)

Timesplitters 2 and 3 Portal 2 Kirby Super Star

games with little to no internet

This is kinda vague and I dont exactly know what you mean by this. Do you mean games that you can play on a single screen? Or games with LAN or private server capability such as Minecraft?

For local co-op games:

• Gauntlet Legends & Dark Legacy
• Halo 1-Reach
• Dragon's Crown
• Helldivers 1 (broken in RPCS3 unfortunately, but if you have a PS3 can be played offline)
• The Legend of Zelda Four Sword Adventure
• Any Call of Duty Zombies (beginning with World At War)

Borderlands 2 is great for co-op, but I'm not sure if you can do local splitscreen if that's what you're looking for.

Couch Coop?

• Smash bros
• Castle crashers
• mario Kart 64 versus mode
• frantics
• rabbits party of legends (only good the first time, so make it count!)
• mario kart double dash
• bud Spencer & Terrence hill slaps and beans
• a Pokémon nutzlocke soullock challange
• playing any game where one has the right and the other one the left joy con (fun if 5 people and 2 are gaming pros and they are forced to share one controller)
• screen cheat
• lovers in a dangerous space time
• bayblade V-Force
• digimon rumble arena 2
• digimon world 4

Some of my favourites…

• TimeSplitters: Future Perfect - PS2
• Sunset Riders - Arcade
• Cadillacs and Dinosaurs - Arcade

If you're up for a 90's classic you could try Goof Troop for the SNES.

N+ for the xbone is pretty good. It's very simple but addictive.

If you can emulate get Mashed: Fully loaded for the PS2

I used to play some monkey game at uni but we were always stoned so I can't remember exactly. Mebbies it's something like Monkey ball tennis? There was loads of games within

Nucleus Coop (for Windows only unfortunately) makes lots of games that ordinarily don't have offline splitscreen to work in that way.

Rainbow Six 1 (GOG) and 3 (Steam) are both playable via LAN and some of my favorite co-op games ever. The first game may require hacking some easy-to-read level config files to make them finishable, but 3 doesn't have that problem. Rainbow Six: Rogue Spear isn't available for purchase anymore. I hear SWAT 4 (GOG) is great for scratching this itch too, but I haven't played it myself.

While not so story focused, you could also co-op Star Wars: Battlefront II; the good one, from 2005 (GOG).

Brothers: A Tale of Two Sons - pretty cool as you can play on 1 controller.
Star Wars Battlefront 2 (OG) - have awesome memories with it.
Earth Defence Force 4 or 5 - over the top bug extermination and built in split screen even on PC.
Last thing I can recommend is Saints Row 2, 3 and 4 (especially 3) - but you need something like Nucleus to play on the same device.

Spelunky2 is good, up to 4 players.

Very hard but definitely worth persevering with.

Trine

Broforce

Gang Beasts

It Takes Two

Split Fiction

Quake and Quake 2 have a bunch of co-op modes and they have been updated for crossplay on modern systems. I was just running some of the newer map packs with my buddies last night. Quake is $4 on Humble right now.

New classic Doom versions have very good split screen options

Personally i like Duck Game for parties of 4+

I posted a review here earlier this year, but A Way Out was an excellent 2-player co-op game! I really enjoyed it. Story rich puzzles with some action interspersed. And it's split-screen even if you're playing online, so you can see what your partner is up to and coordinate with them. The ending was heart-wrenching too! Such an emotionally impacting story. Check out my review for a spoiler-free intro to that game.