5) Call of Duty 4: Modern Warfare (2007)
Maybe it was the constant drip-feed of unlocks and upgrades that kept players coming back. Maybe it was the finely-crafted selection of now-iconic maps. Or maybe it was the sublime, gung-ho gameplay that went at a mile a minute.
We're betting it was a combination of all three. Modern Warfare set the bar for multiplayer, and console shooters have been playing catch-up ever since - future Call of Duty games included.
4) Halo: Combat Evolved (2001)
Great first-person shooters were mostly only found on computers and controlled with a keyboard and mouse – well, at least until Halo came around. Bungie's juggernaut needs no introduction, and it's the biggest reason that Microsoft still makes consoles today. But the sci-fi series deserves all the praise in the world for delivering an epic, controller-based campaign, and giving us reason to haul our giant original Xbox's around for console LAN parties. (Note: Anniversary Edition shown)
3) BioShock (2007)
BioShock was not your average FPS game. Packed with allusions to author Ayn Rand's Objectivism philosophy and George Orwell's Nineteen Eighty-Four, and with a gorgeous setting inspired by the Art Deco architectural movement, this was about as far away as possible from the usual bad-guy-aliens-have-taken-over-the-Earth fare that makes up most shooters.
Not that it entirely thumbed its nose at FPS conventions: you still spent plenty of time walking down tunnels and fighting assorted baddies, in this case the genetically modified inhabitants of the underwater city of Rapture. But in addition to also giving you a fully realised setting and backstory, BioShock also opened up the gameplay, splicing in RPG elements and giving the player real moral decisions to make.
In equal parts innovative, influential and inspirational, it was an FPS that stayed with you for long after you'd finished it.
2) Doom (1993)
Doom may have followed in Wolfenstein 3D's footsteps, but it remains without doubt the most influential of all FPS games and defined the genre for years to come.
It was the first such game to serve up proper 3D, or at least to do so in a smooth, playable way; it standardised the FPS weapon set of pistol, shotgun, machine gun, energy, rocket launcher and totally-insane-last-resort weapon; it made blood and gore key parts of the FPS experience; it birthed the idea of varied baddies who needed to be taken down in different ways and possibly with different weapons; it basically set the tone for everything that followed for years after.
None of that would've happened if Doom had been anything other than brilliant, but it was absolutely that. The maps were huge, sprawling things that could often be explored in a myriad of ways. There were secrets hidden throughout, some of which offered up much-needed power-ups and some of which merely helped you towards that elusive 100% completion. The graphics were unbelievably good for the time. And the difficulty curve was judged just perfectly, leaving you constantly up against it but never quite down and out. Well alright, quite often down and out, but never without hope that you could conquer this level with just one more go.
In short, it was a near-perfect game in every way. Shame about the movie, though...
1) Half-Life 2 (2004)
There are many reasons why people regularly proclaim Half-Life 2 to be one of the greatest games ever, and they're all valid. The graphics were fantastic for the time, the storyline was well written, the characters were well-rounded, and the enemies and weapons were impressively varied. And it's a huge game with a lot going on. But really the reason why we're naming Half-Life 2 as our greatest FPS game ever is simple: the gameplay.
Yeah, it really is that easy.
Look, you play a game to enjoy it, right? And you'll enjoy Half-Life 2 like no other FPS game. The level design is simply incredible. It's mainly quite linear, but there are always so many ways you can approach a particular setting that it never feels like it. The overall pacing is unmatched, with some levels offering tense stealth-based challenges and others plunging you into mass firefights. It flows like the best films or the best books. It's really that good.
Oh, and the Gravity Gun. It also wins because the Gravity Gun is the single greatest video game weapon of all time. Oh how we wish Half-Life 3 would one day arrive...