I'm gonna say Xbox 360 (and its generation). Why? Well because it's the console me and most of my friends had, hence finding people to play with was easy. Couch coop was possible and easy due to everyone having controllers. Besides having amazing games and backwards compatibility with the Xbox. PS3 was also a very strong console and the Wii was one of the most sold consoles ever, being a quite unique console with full GameCube backwards compatibility.