Left 4 Dead 2
Half-Life 2
Team Fortress 2
Counter-Strike: Source
Portal
Half-Life 2: Episode Two
Left 4 Dead
Half-Life 2: Episode One
The Orange Box
Day of Defeat: Source
Half-Life 2: Deathmatch
Valve Complete Pack
Counter-Strike Complete
Garry’s Mod + Team Fortress 2
Half-Life 2 Episode Pack
Half-Life Complete
Half-Life 2 Complete
Counter-Strike: Source + Garry’s Mod
Source Multiplayer Pack
Team Fortress Complete
It’s always frustrating to read a list of the best Steam mods, as most top lists tend to be composed primarily of unreleased mods such as Black Mesa Source and Mario Kart Source. Â Don’t get me wrong, those look awesome – but it’s been years since they were first announced and they remain frustratingly unreleased.
I have put together a ranked list of what I consider to be the best free mods currently out – no waiting, you can play these free right now. Â Feel free to comment if I missed a good one, or disagree with their rankings. Each of these mods requires that you have Steam installed in order to play (some also require that you own a Source title – list of source titles).
Alien Swarm is one of the best multi-player titles to come out this year.  It sports a unique top-down interface (it’s possibly to play it FPS if you prefer). One can easily put 40 hours into the game playing through each of the different classes, achievements, and difficulty levels.  What really set this mod apart is that it was released free of charge.  One does not even need to own another Source game (unlike most of the other mods in this list).  This game is an easy choice for the top spot. It also has by far, the largest number of active gamers at any one time of all the mods.
Zombie Panic! is an awesome amazing astounding mod that allows a large group of players to engage in a large scale multi player team battle. Â Every match at least one player spawns as a primary Zombie, and the rest as a group of scattered survivors. Â The survivors must do everything they can to barricade themselves and work together to hold off the ever growing Zombie swarm. Â Each survivor that dies or is bitten respawns as a Zombie. The developers have announced their intentions to release a sequel call Contagion. Â The game is hugely popular, and has several hundred players playing it at any given time.
Insurgency is an extremely realistic CS-style online FPS that pits insurgents against the US military. Â Strong squad tactics, and one hit kills may leave those used to Counter Strike frustrated, but after playing a few rounds the game really starts to draw the player into it’s realistic battle environment. The game has a fairly strong multiplayer community, with a steady group of populated servers always available.
This game is ridiculous.  It’s also ridiculously fun.  You choose from three  different player teams to be either a Pirate, a Knight, or – yes you guessed it, a Viking.  You’re probably wondering if that screenshot really shows a Pirate flying through the air with the exploded remains of his Parrot floating over a red bearded Viking.  The answer is yes, and so yes, you should go download this multiplayer deathmatch and enjoy.  It’s rough, but it’s fun and there’s usually almost as many playing this as Insurgency (This is the mod everyone goes to when they get frustrated by Insurgency’s difficulty.
Unlike Half Life 2 Lost Coast, another free Half Life title, HL2 Deathmatch is a game which one can play for hours and have fun with. Â Who wouldn’t want to spend some time playing an online multiplayer game that allows you to frag others by tossing a toilet? Half Life 2: DM is given out to anyone that owns either an ATI video card or an NVIDIA one. Â Like all other Valve games, Steam is required in order to download and install the game.
The game is fast paced, and purely multiplayer. Â If you’re looking for an FPS online deathmatch with solid controls, this game will fit the bill.
One unfortunate thing to note – the free version of the game does not qualify for free access to mods, so you’ll still need to purchase a Source engine game in order to play popular mods like Zombie Panic.
You will also receive some other games free depending on your video card. Â Also, there’s the HL2 Deathmatch University that host these map packs.
Longer Description:
Half-Life 2 was released without a multiplayer component, and was instead packaged with Counter-Strike: Source. A few weeks later, Valve released Half-Life 2: Deathmatch on Steam. The goal of the game is to kill as many other players as possible, using a variety of means, in either free-for-all or team-based matches.[28] A subsequent update to the game added an additional map and three new weapons.
Fast multiplayer action set in the Half-Life 2 universe! HL2’s physics adds a new dimension to deathmatch play. Play straight deathmatch or try Combine vs. Resistance teamplay. Toss a toilet at your friend today!
Half Life 2 was an amazing follow up to the original Half Life series. Â As a way of giving gamers a taste of many of the HL2’s new features, Half Life 2: Lost Coast is given out to anyone that owns either an ATI video card or an NVIDIA one. Â Like all other Valve games, Steam is required in order to download and install the game.
The game is visually beautiful, and fun to explore – don’t expect too much as far as gameplay goes – the entire thing can be finished in under ten minutes even if you go at a snail’s pace.
One unfortunate thing to note – the free version of the game does not qualify for free access to mods, so you’ll still need to purchase a Source engine game in order to play popular mods like Zombie Panic.
You will also receive some other games free depending on your video card.
Longer Description:
Half-Life 2: Lost Coast is a small additional level for the 2004 first-person shooter video game Half-Life 2. Developed by Valve Software, it was released on October 27, 2005, through the Steam content delivery service as a free download to owners of the Microsoft Windows version of Half-Life 2. Lost Coast serves as a technology demonstration, specifically showcasing the high dynamic range rendering implemented in the Source engine. The level was designed with a variety of appropriate environments to emphasize these effects. In addition, Lost Coast was the first video game developed by Valve to allow developers to explain various elements of design as the player progresses through the level.
Lost Coast follows Half-Life protagonist Gordon Freeman as he travels up a coastal cliff to destroy a Combine artillery launcher in a monastery, which is firing on a nearby town. The Lost Coast level was originally created for Half-Life 2, but was ultimately removed from the game. As a result, it has several minor story details that were not included in Half-Life 2. The level received a generally positive reception, and there was consensus among reviewers that the new features included in Lost Coast should be integrated into future games released by Valve.
Half-Life 2: Lost Coast is a small additional level for the 2004 first-person shooter video game Half-Life 2. Developed by Valve Software, it was released on October 27, 2005, through the Steam content delivery service as a free download to owners of the Microsoft Windows version of Half-Life 2. Lost Coast serves as a technology demonstration, specifically showcasing the high dynamic range rendering implemented in the Source engine. The level was designed with a variety of appropriate environments to emphasize these effects. In addition, Lost Coast was the first video game developed by Valve to allow developers to explain various elements of design as the player progresses through the level.Lost Coast follows Half-Life protagonist Gordon Freeman as he travels up a coastal cliff to destroy a Combine artillery launcher in a monastery, which is firing on a nearby town. The Lost Coast level was originally created for Half-Life 2, but was ultimately removed from the game. As a result, it has several minor story details that were not included in Half-Life 2. The level received a generally positive reception, and there was consensus among reviewers that the new features included in Lost Coast should be integrated into future games released by Valve.
