One of the best coop games was Halo 3.
My fav multiplayer game was MGO (mgs4)

Spection wrote Best co-op game I've ever played is Conflict Desert Storm. Has anybody here played it? It was on the PS2.

I don't know if League of Legends counts but that's my favourite multiplayer game right now.

Classic Games:

COOP: Conflict Desert Storm 1 and 2
Multiplayer: SOCOM 1 - 3/Battlefield Modern Combat 2
MMO: Probably Runescape back in the day.

Now:

COOP: I like the COOP Splinter Cell games.
Multiplayer: Battlefield 4
MMO: Probably Sheiya or Dekaron

GMC wrote The best coop I would say is left 4 dead

L4D series is fun with random texture mods and stuff. Good pick!

-Swift wrote My favorite co-op game has to be Left 4 Dead.

My favorite MMORGP is LoL, I love to watch is but I cant play it worth a damn.

Yeah LoL speaks for itself, It can only be played by Legends, I can't play it either.

I love Resident Evil 6, and Dead Island. Only the first one. I hated riptide.

Bets wrote Halo 3 was the best game ever in its time, hands down.

Fully agreed man, I miss playing it at times.

I wouldn't say this game was the best co-op I've played, but I really enjoyed playing the arcade game Happy Wars.

302 wrote The co-op game I'm really into now with my friends is definitely unturned.

I'm kinda interested in that game, It's a like a DayZ/Minecraft mixture after watching vids.

My favorite Multiplayer game would be either Halo 3 or Call of Duty 4. Mainly H3, but I played both those games so damn much!