Easily one of the best co-op shooters and possibly the best zombie game ever. The amount of character dialogue per campaign and the unique nature of the special infected, combined with the fluid gameplay makes for an experience like no other. L4D2 also includes all of the L4D1 missions, all with the same great experience. Be warned, though, as this game will brutally punish you if you stray away from your team or if you don't work together with your teammates. The steam workshop mods make this game infinitely replayable, and it goes on sale almost all the time. All of this for $5 (when on sale) is a no-brainer. Make L4D3 please Valve.

Easily one of the best co-op shooters and possibly the best zombie game ever. The amount of character dialogue per campaign and the unique nature of the special infected, combined with the fluid gameplay makes for an experience like no other. L4D2 also includes all of the L4D1 missions, all with the same great experience. Be warned, though, as this game will brutally punish you if you stray away from your team or if you don't work together with your teammates. The steam workshop mods make this game infinitely replayable, and it goes on sale almost all the time. All of this for $5 (when on sale) is a no-brainer. Make L4D3 please Valve.