Left 4 Dead is an amazing game. It forces players to cooperate but not in a way that it feels so forced that the fun rating goes down. Your HAVE to rely on your teammates or else you will not survive. You can not go Rambo on everyone and expect to stay alive. While this type of cooperative multiplayer might not be for everyone, or might not work anytime due to retarded team-mates when it does work it is extremely fun and satisfying.
When playing as the survivors for my first time I played this game like it was halo. I neglected my teammates and ran through the apartment complex in the "No Mercy" campaign. When I was on the second floor to the bottom I was pounced by a hunter and my teammates had to rescue me. So it came to me that this was not
SUPER ZOMBIE APOCALYPSE CHAINSAW DEATH GORE . This game was definably not that title. I soon learned to rely on my teammates and to help them out when they were in trouble. The use of the AI Director in the game is amazing. There are "peak" moments where the action heats up and zombies start flooding in like shoppers on Black Friday. So when playing through one campaign that I had previously played before. I told my team to get into a corner and watch for the zombies but I was surprised when only a few came. The AI director also controls when and where the tank will spawn along with weapons and items. "He" determines the spawn places of weapons and items due to how the team is doing. For example if you are progressing slowly and seem to be having a hard time the AI Director will have there be less zombies and more useful items. Valve pulled of the AI Director really well and it makes for a really fun experience each time you go through.
Playing as Boss Infected has been a really fun and satisfying gaming experience. Basically you get to play as either a Smoker ( a tall zombie that snags Survivors with his tongue), a Hunter ( an agile zombie that can leap high distances and pounces on Survivors), and a Boomer ( a fat-ass zombie that explodes when shot and when he throws up it attracts zombies). When you spawn you will randomly become one of these three boss infected. The classes are all different and fun to play as, however I do find the Hunter to be the most occurring boss infected. My favorite person to play as is the boomer because when you barf on the survivors and it attracts loads of zombies it is extremely satisfying especially when you explode on them afterwards. When your team ends up owning all the survivors to the point where it is inevitable that they will all die it is extremely fun and makes for a very satisfying experience. Every once and a while someone playing on the Infected will randomly be selected to play as the Tank. This usually happens at climax moments or when there are tons of infected but who-ever is the lucky person that will get to play the Tank will have loads of fun. The tank is basically the hulk, but a zombie. He can throw cars and maul people down. On the finale of the "No Mercy" campaign the survivors are on a hospital rooftop waiting for a helicopter to rescue them. Knocking the survivors off the rooftop is the most fun thing you can do in this game.
So if you have the money to spare buy L4D now.