The FPS - or first-person shooter - is gaming's most popular genre, and with good reason. There aren't many better ways to spend a weekend pretending to be a highly trained badass, after all, and FPS games allow you to do it from the best view possible.
Over the years we've had some incredible experiences from this genre, so we've rounded up 20 of the best of all time.
And yes, obviously Doom's in there. It wouldn't be a 'best FPS list' without it.
Whether you play the original version or CSGO, one thing is certain in this tactical online shooter: you're probably going to lose. Also, love it. You'll really love it. As well as losing.
Get together a team of four and take on some of the most frantic FPS/RPG hybrid gameplay you're ever likely to see.
It's also nice to play a game that has a sense of humour, of course.
Duke Nukem 3D
Ah, the old classic - and it's still fun to this day, that much we can guarantee.
Exploration, one-liners, strippers, pig cops - all good.
A unique proposition in the world of shooters, one in that you don't really shoot that much, and two in that you can get through most (if not all) of the game without killing anyone.
It's also gorgeous, stylish and all those other neat extra bits.
Far Cry 4
Look at that image and say you don't want to play this game. If you do so, you're a liar.
Far Cry perfected its formula by the fourth instalment- it's a huge world to explore, it's massively addictive and you can ride elephants.
For some the second game is better, and for others even the third one, Bioshock Infinite, trumps the first two. But 2007's BioShock started it, and it's still incredible.
Atmospheric up the wazoo, it's scary, dark and beautiful in equal measure. Rumours of a BioShock anniversary pack are circling the web - we urge you to snap it up if (when) it arrives.
There's a reason this is always mentioned in almost ever 'best of' video game list: because it's one of the best first-person shooters ever made, even though it came out back in 2004.
It raised the bar for everything, and most are still playing catch-up.
We've gone with Halo 3 as the best in Master Chief's series, but you might go otherwise. For us the 360 game is nigh-on flawless.
If you can't pick just one, go with the Halo Master Chief Collection on Xbox One - then you have them all in one package, except for the odd spin-off and Halo 5.
Call of Duty 4: Modern Warfare
Remember the time before Call of Duty was the biggest series in the world? Well if you don't here's the short story: it wasn't huge, then Modern Warfare hit and everything changed.
Other games in the series have perfected multiplayer, but for us it's the first MW that takes the trophy as the most important in the series.
You're not seeing Goldeneye 007 in this list for two good reasons: one, Perfect Dark outplayed it in too many ways to list, and two, you can't even get Goldeneye legally these days (unless you've still got a copy in your attic).
As such, it's up to the futuristic spy romp to carry the weight... of victory.
The original changed gaming forever, but the second Quake is the best of the series for single-player fun.
A fast, tight campaign that's still great to this day, it's gone down in history as one of the most important titles ever made.
One for the PC gamers: Planetside 2 is all about gigantic battles by air and land, with hundreds of players clashing in an endless war. It's an amazing experience.
Best of all, it's free. Yes, there are in-game purchases, but you don't need to make any to have a blast.
One of the PS2/Xbox/Gamecube's best, Timesplitters 2 takes us back to an era just before console shooters went online in a big way and you started losing to US kids who swore they did terrible things to "your mom".
Four-player split-screen was, and still is, an incredible way to spend a Friday night. Also, it has monkeys.
Left 4 Dead 2
Turns out putting four people together and making them survive over a series of different zombie-infested levels is even better than it sounds on paper - and it's still hugely popular today, six years after it launched. It just won't die.
The thinking person's FPS, SWAT 4 doesn't reward you for the most headshots - it rewards you for planning, being careful and following police procedure.
That does sound dull, but we promise you this is one of the greatest, most considered FPS games ever.
Well, it's Doom. There isn't much else to say beyond that. Doom changed games forever, and Doom is still amazing fun. You can even play it on your phone.
Insert whichever number at the end you want - 2003, 3, the upcoming one, whatever, they're all great. Well maybe not the upcoming one, but only because we don't know right now.
Unreal Tournament is mulitplayer gaming how it should be done, and still has a healthy player base even though it's rather old now.
What do you mean it's 17-years-old?! Lord...
Team Fortress 2
TF2 took forever to arrive, then blew us all away when it did. Class-based team multiplayer boiled down to its absolute (best) essentials, it is ludicrously popular and ludicrously good.
It's another free game, and one you can play easily without spending a penny. Unless you want hats. Then you're going to be spending loads.
While Quake 2 did the single-player best, Quake 3 was the game that nailed multiplayer for the series.
A pure online shooter (with some ignorable offline stuff), even though it came out in 1999 people still play it a lot and hold it as the standard for online shooters.
The fourth game is technically better, but the third game is where most of the fun has been had - and still is had.
Not only does it have some of the best multiplayer in any game ever, Battlefield 3 also has a single-player game that you'll want to play. If all game developers could take note, that'd be great.