There are some games that have the illustrious honor of becoming the platform for an even greater experience. Though copies are sold and developers sucked off, the efforts of the modding communities have produced countless hundreds of thousands of hours of playtime, and here are the top 5 best mods ever made. 5. Alien Swarm (Unreal Tournament 2004): Alien Swarm is a pulse pounding cooperative mod that finally allows the player to scream, "MARINES, WE ARE LEAVING!" and feel satisfied. A top down shooter, Alien Swarm boasted a class based game that had the players moving through corridors and catwalks trying to complete objectives before the Aliens got them. The gameplay is tense as players choose items and weapons kits to complete the mission, because there is never enough ammo...EVER! What really held this mod back was the lack of players online, but the offline never dissapointed. 4. Natural Selection (Half-Life): An rts fps you say? Intrigue... Though there were some quirky bugs, Natural Selection was an absolute blast to play. A humans vs. aliens showdown on a small environment, both teams attempt to out shoot and out think the other. It was a lot of fun if your team didn't suck, but generally the Humans always had a crappy commander. 3. Desert Combat (Battlefield 1942): Desert Combat was what Battlefield 2 wishes it was. The combat is quick, the vehicles are fun, the weapon kits are strategically designed, and god how I love those helicopters, took skill to fly those. The fellows who designed this mod are making a game for the Playstation 3, so I hope it turns out as well as this one. 2. Counter-Strike (Half-Life): If you haven't heard of Counter-Strike by now, you probably hit this site through google search, just click the back button. Copied, tweeked, reformulated, copied again, and played to death, Counter-Strike featured an insatiable mix of near realism gameplay. It was an amazing accomplishment for the creator, Gooseman, who is now very pleased with his platinum hos. For a bit of trivia, did you know that CS has become an arcade game...IN JAPAN? I'm sure everyone who started reading this expected CS to be number one, so for all three of you, here is a kick in the pants. 1. Team Fortress Classic (Half-Life): The cream of the crop, TFC started as an experiment at Valve to test the ability of the software development kit, and ended up killing Half-Life multiplayer. Though it's popularity waned in the presence of Counter-Strike, TFC's gameplay is delicious and strategic. Honorable mentions are due, as I have a few mods that I kept near and dear to my heart. Tactical-Ops (Unreal Tournament): Counter-Strike without the mad dash to the camp points, Tactical-Ops added a more action oriented style of play with real world weapons. Don't expect the Desert Eagle to roll you with one head shot. The most recent release is a piece of garbage, but before it went commercial, it was classic beyond classic. The Opera (Half-Life): The Opera featured the kind of Gun-Fu that I have yet to see replicated in any other game. The moves all felt satisfying, because you couldn't just dive and shoot, THERE WERE RULES! Diving actually made you feel like you were diving, restricting your movement and making it harder to shoot. Rolling on the ground was a desperate attempt to not be shot, but when you killed, the style could never be replicated. I had heard the mod was coming out for Unreal Tournament, but I think it collapsed. Pitty. Desert Crisis (Half-Life): I don't know why I liked this mod, the developers were jerk faces, the community were jerk faces, the weapons were unbalanced, the gameplay was awful, only a few of the maps actually worked as intended, and yet there was something lucid about the process that kept me hooked. Still, it blows, and don't touch it. Firearms (Half-Life): Firearms was the game that military buffs jerk off to before they go to sleep. Way to realistic for the average fan, Firearms featured a metric ton of guns, bleeding, breathing, stances, and an rpg system that was pretty nifty. It was a difficult game to play starting out, because the uniforms looked almost exactly identical. Infiltration (Unreal Tournament): Though it wasn't particularly as realistic as Firearms, it introduced the concept of using the iron sights to aim a gun, and gun collision, meaning that if your gun hit the door, you had to back up, making smaller weapons ideal for indoor environments. It was an interesting game, and a lot of fun to play offline.