Possibly the only Modern Game that is still updated without a sequel.

User Rating: 10 | Killing Floor PC
As the title suggests, this game never gets old. Tripwire is still making advancements and new things. I remember playing this from day one when there were only 6 maps and there are now over 20. They have also added new weapons and recently a new game mode. The 6 player co-op is awesome and they are always adding unique achievements to the game and following steam's theme (portal 2, steamland). The graphics, sounds, and engine are not updated, but all of the new content still makes it worth playing today. The price on steam is always going on sale and the game can be played on Linux, Mac, or Windows with cross platform multiplayer. The multiplayer mode is unique too. It has a coop required survive feel to it and it is nearly impossible to win without communicating to your team mates. Every now and then I get a smug 14 year old, but for the most part it is veterans who will most likely help you out or thank you for your performance. The guns are actual real life guns and it is a nice feel, I believe they recycled a lot of the game's technology from Red Orchestra. I would recommend this game to any fan of doom, fps action, horror, pc games, rpgs, or people who enjoy just plain grabbing a gun and killing something.