Left 4 Dead 2
Left 4 Dead 2 was Valve perfecting a four-player zombie survival game created by Turtle Rock for the original Left 4 Dead. With its AI “Director,” every co-op game plays out completely differently, with the infamous zombie types (everyone remembers the Boomer, but then silently shudders when you remind them of the Witch) spawned in according to how you’re playing.
On top of that, all four player characters are excellently voiced with thousands of possible lines, spoken to match the situation in which they currently find themselves. The result is an utterly terrifying, completely compelling game.
