Online Shooters bring death matches, capture the flag matches, bots and mods to the online gaming arena. Thus far, the online shooter genre has been more mainstream than the MMOFPS genre due in large part to the success of blockbuster games via retail like the Battlefield and Unreal Tournament franchises.

Online Shooter Showdown
Sixteen of the top multiplayer FPS and TPS games go head-to-head to determine which one is the best. The 2012 tournament is currently in the second round. Find out who faces who! 

Counter-Strike: Source Download: Yes Graphics: 3D Free or Pay: Must be bought. Expands on one of the big boys of multiplayer gaming.   Online Shooter Reviews The place to vote on Shooter Showdown matches and to find reviews by players. Wolf Team Download: Yes Graphics: 3D Free or Pay: Free. Transform into a werewolf!

Planetside 2
Download: Yes
Graphics: 3D
Free or Pay: Free
Sequel to the successful MMOFPS game.

Battlefield 3
Download: Buy
Graphics: 3D
Free or Pay: Pay
Another game in the vaunted BF franchise.

Firefall
Download: Yes
Graphics: 3D
Free or Pay: Free
Considered by many to be one of the shooters with the brightest futures. Has been in development for years.

Alliance of Valiant Arms (AVA)
Download: Yes
Graphics: 3D
Free or Pay: Free
Free FPS with many modes and features.

Cross Fire
Download: Yes
Graphics: 3D
Free or Pay: Free
Military online FPS with a special mode called Ghost Match.

World of Tanks
World of Tanks Key Giveaway With a Tank
Forum
A team-based massively multiplayer online action game dedicated to armored warfare.

WarRock
Download: Yes
Graphics: 3D
Free or Pay: Free
Free online shooter with the option to buy more high-powered weapons.

Team Fortress 2
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
One of the best team shooters ever. Sports cartoon-style graphics and loads of personality.

Battlefield Heroes
Graphics: 3D
Item Mall: No
Download: Yes
Cartoon multiplayer shooter that could be a smash hit with both casual and hardcore gamers when it is released. 

CrimeCraft
Graphics: 3D
Item Mall: Yes
Download: Yes
CrimeCraft Starter Key Giveaway  
Next-gen game that can be classified as an online shooter or a MMOFPS. Is now free.

Crysis
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
One of the best looking games ever, but not for all PCs. Focused on single player, but does have a multiplayer mode.

Combat Arms
Download: Yes
Graphics: 3D
Free or Pay: Free
Players can battle up to 15 others and weapons can be modified.

Quake Live
Download: Browser
Graphics: 3D
Free or Pay: Free
Social shooter that can be played in a browser.

Left 4 Dead
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Survival horror game that focuses on the team rather than the individual. Left 4 Dead has one of the best coop modes of all time.

Counter-Strike: Condition Zero
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Expands on the Counter-Strike franchise. 

Battlefield 2142
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Takes the vaunted Battlefield series into the future with high tech weapons and vehicles.

Operation 7
Download: Yes
Graphics: 3D
Free or Pay: Free
Online FPS where you can build weapons from parts made in the real world.

S4 League
Download: Yes
Graphics: 3D
Free or Pay: Free
MMOTPS with cartoon graphics and a sports theme.

Battlefield Heroes
Download: Yes
Graphics: 3D
Free or Pay: Free
Third person shooter with cartoon graphics and MMO abilities that is currently in development.

FEAR Combat
Download: Yes
Graphics: 3D
Free or Pay: Free
Free multiplayer version of FEAR.

Soldier Front
Download: Yes
Graphics: 3D
Free or Pay: Free
Freebie that features distinctive weapons from task force characters. 

Unreal Tournament 3
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
One of the best shooter franchises boasts a new Warfare mode and high-tech vehicles.

Tremulous
Download: Yes
Graphics: 3D
Free or Pay: Free
Free open source game that combines FPS elements with RTS elements. 

Battlefield 2  
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Not only outdoes the original and BattleField 1942 and Battlefield Vietnam but has to rank as one of the best shooters yet. 

FEAR Combat
Download: Yes
Graphics: 3D
Free or Pay: Free
Free multiplayer version of FEAR.

Doom 3
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
When you think of Doom 3, think power and fear! D3 does the vaunted franchise proud with amazingly intense game play and simply awesome graphics. You won't be armed to the teeth with weapons where you can mow down hapless monsters. Instead, you will need to tough it out corridor-by-corridor in order to survive. Needless to say, you will need an extremely powerful PC with a state-of-the art graphics card to fully experience this new classic.   

Control Monger
Download: Yes
Graphics: 3D
Free or Pay: Free
Free online FPS where bots go to war! 

FarCry
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Forget dungy dungeons and drab planets, this beautiful shooter takes place in the sunny tropics. 

S.T.A.L.K.E.R
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Highly-anticipated shooter that should be brilliant. 

Half-Life 2
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
The long-awaited sequel to one of the best games ever. Will cater to the mod community even more this time. 

Tribes Series
Download: Yes
Graphics: 3D
Free or Pay: Some of the older versions are now free.
One of the best multiplayer shooter franchises ever. Believe it or not, Tribes is actually a spin-off from the failed Sierra game, Starsiege. You can now download Tribes 1 and 2 for free or you can wait on the latest installment in the series, Tribes: Vengeance. 

Unreal II
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
Although a multiplayer version did not originally ship with the game, a multiplayer version was thankfully added for free.

America's Army 
Download: Yes
Graphics: 3D
Free or Pay: Free
Download the full version of one of the best multiplayer shooters available.

PlanetSide
Download: Yes
Graphics: 3D
Free or Pay: Must be bought.
First person shooter MMORPG that features vehicles, squads, and hacking. The current leader of the emerging MMOFPS genre. 

Unreal Tournament Cheats and Strategies Blow away the competition with this wide assortment of cheats and strategies for one of the games that revolutionized the online shooter genre. Unreal Tournament Review Although not the first, UT established the multiplayer-focused shooter genre. Unreal Tournament 2004 Download: Yes Graphics: 3D Free or Pay: Must be bought. Once the best online shooter on the Internet with free online game play. Takes an extreme sports franchise twist along with the introduction of vehicles to make this installment one of the best in the series thus far. Half-Life Download: Yes Graphics: 3D Free or Pay: Must be bought. The undisputed king of mods in the FPS genre or any genre for that matter. No game has near the number of mods as Half-Life has. This has contributed to Half-Life being recognized as one of the best games ever.