Lots of us use Steam and are in the Steam group, but we never utilize it (by the way I\'m TheCaucasianAsian) since we don\'t have any games that are similar. Let\'s make a continually growing list of games, especially since the Summer Encore sale is on today and tomorrow.

4 player co-op:
Borderlands/2/Pre-Sequel
Payday/2
Dungeon Defenders/2 (2 should be hitting free to play once it\'s out of early access)
Castle Crashers
Left 4 Dead/2
CoD Zombies (World at War or Black Ops/2)

For larger groups (5+):
[FREE] Team Fortress 2
Grand Theft Auto V (~25 people)
Killing Floor/2 (6 players)
CSGO
Left 4 Dead/2 (versus mode allows 4v4)
Tabletop Simulator (8 players)
Torchlight/2 (6 players)
Ark: Survival Evolved (70 players, requires a server, requires a beefy computer)
Chivalry: Medieval Warfare
Garry\'s Mod
Dota 2/League of Legends
Minecraft (heh)
Space Engineers
Medieval Engineers
Arma 2/3

Those are all of the games that I can think of. If you have any of these games, comment them and we can figure out which games we have in common (or consider buying some of them this sale, these are big-name titles and most should be on sale right now, June 20th and June 21st)