Alright.....
I used to have an account on here in like 2010 and just made this one as I was here to see what Yahtzee thought about DUSK. More on that later.
I've had a good look through this thread and a got an idea of what you like in your games: engaging reward feedback loops and immediacy.
Hence I have the following to recommend/
Cave Story (AKA Dokatsu Montongari)
Published in 2004, this one game kickstarted the indie dev movement by being made by one dude by himself over three years. A richly detailed 2D Metroidvania, this game has amazing level design, engrossing combat, beautiful music, and a surprisingly deep story with multiple endings. You can find it out there for free or pay on steam for a version with updated graphics and multiple player characters (though IMO the original art style looks best). Anyone who wants to make games should play this game as an example of the length and attention to detail required.
Doom 2016.
BEST. GAME. OF. 2016.
The only comments I have here are some hardcore AFPS players found the game's habit of locking you in arenas confining but even those people are a minority even in their own communities of people still playing Quakeworld and CPMA (Quake 3 pro mod). That should tell you how fucking good this game is.
Bunker Punks.
Endlessly replayable, this AFPS-Rougelike hybrid is one of only two of such a genre that get it right. Levels are RNG, abilities are upgraded via your home base, movement is fast, and all items and enermies are sprites, making the game feel like a really complex Doom 2 mod. You do have a 2 weapon limit but the game just chucks weapons at you so much that it's not a problem.
Ziggurat.
The other of the two to get it right (STRAFE does not count, let us not go there). Ziggurat has a fantasy theme and is entirely projectile based. Combat feels like a fully-3D Heretic or Hexen sometimes though being a rougelike the levels are not the same. I will ad a caveat that this game is much more heavy on the RNG elements then BP above and often feels like complete bullshit when you endlessly die in the opening couple of levels. Still, press on and (mostly by unlocking better characters to run with) the game opens up enormously.
DUSK.
The sleeper release of of 2017. You like Quake? You wanna play Quake but set in a town controlled by cultists? Yeah, you'll like this one. It was even made to look like it was from 1996 and has a fake DOS intro and things like downscaling and pixelisation options. FPS of 2017 AND 2018 due to the staggered release. 33 well-designed levels plus multiplayer.
QUICK PLUG FOR MY CHANNEL https://www.youtube.com/watch?v=WFWTe_x9Gko&
Rainbow Six: Siege
People are recommending this for a reason, it's probably the most absorbing and tactically minded shooter on the market, barring simulations like ARMA III or Insurgency, Red Orchestra, or Day Of Infamy. Or Rising Storm.
Ok so it's not THE most tactical but unlike those games it's also not insanely hardcore to the point of masochism and nihilistic thoughts as you die for the 12th time in a row without firing a single shot back....
AHEM. Siege is slow, tense, methodical, everything that most modern military shooters aren't.
Overwatch.
It's TF2 with 25 different fuckin characters. It and it's clones like Paladins are straight up MOBA FPSs. Give them ago if that sounds appealing. The gameplay is quite solid and the meta changes a lot.
Dirty Bomb.
I sunk almost 200 hours into this 100% free game before my CSGO addiction got it's teeth into me. Did you ever play RCTW? Or Wolfeinstien: Enemy Territory? Same dev team. Fast, fluid, objective-based combat with walljumping, bhopping, and all those skill-based good things. 100% free, no pay to win bullshit like in many other games in the free FPS space.
Finally I'll end by saying something about Prey.
Prey is...well it tries to be System Shock 2. And it's stunning to look at with a very unique 'art-deco-meets east asian' style in it's environments. However, the difficulty plateaus mid-game and never really recovers.
Prey is haunting, beautiful, and as tense and exciting as a knife to your balls in a haphazard sexual encounter. However, this tension dissipates when you get used to the enemies and are well stocked up. So long as you recycle everything you'll be fine for supplies. Play it on nightmare difficulty (hardest) or not at all IMO.