This weekend, myself and others will be fighting off hordes of Zombies co-operatively in Valve's latest offering - Left 4 Dead.
The server setup is very straight forward and super easy for players to join - though we are using Hamachi, as the server only allows access to C Class (LAN IPs) addresses.
Update (23/11): The gameplay is incredible. I haven't had this much fun being overrun with enemies and had awesome co-operative gameplay in a long time, with battles of epic proportions and most importantly, L4D has longevity.
With the AI Director, which changes the gameplay every time you play and if Valve can continue to produce new "movies" for consumption, L4D will be on my hard drive for years to come.
Best of all, there is already hope over at l4dmods.com, where you can check out the latest community made content, starting with "Dead Before Dawn - Enter the Mall", which is based off the shopping mall from Zack Snyder's Dawn of the Dead - one of the best Zombie movies ever made.