Lethal company is an obvious choice. I think you need a mod to play with 5 people though.

BattleBit if you liked Battlefield

Well, I'm not sure this is what you're looking for but Tabletop Simulator is a board game simulator that has a diverse category of games in its workshop mod. I'm sure a lot of the games can be played with 5 players.

Of those on sale-

Terraria

Killing Floor (And 2)

Torchlight 2

Raft

Human Fall Flat

Powerwash Simulator

In order of casual friendly at top, to real gaming hours at bottom IMO

Sea of Thieves

Valheim

Project Zomboid

Factorio

Ultimate Chicken Horse

Terraria (I recommend the Thorium mod that add healer and support classes!)

7 Days to die

Phasmophobia is the best. Unfortunately only for four players total.

Talisman Digital Edition

• Six days in Fallujah
• BattleBit
• no man's sky

Don't Starve Together

Stardew Valley I think is up to 5 (the host and 4?), if not then Sunhaven I'm fairly certain it's up to 8, if y'all like farming sim things.

Core Keeper if you want to craft and chill, with some intense combat too sometimes

Lethal company + more company mod. Ready or not. May ruin some friendships..

We have been playing Insurgency Sandstorm, I believe it's up to 8 players coop

Tower Unite this is the game my friends and spend the most time in casually, it has so many mini games and it's just weird too.

Civilisation V if you have a lot of time on your hands.

What about games that you can drop in and play with others. I know dead by daylight, matchmaking is easy for strangers to play together online. There’s got to be more games like that.

@PostWatchBot@lemy.lol

Ready or not.

Not sure if it's on sale but it's awesome