BotW, Mario Odyssey, Horizon Zero Dawn, God of War, Spider man, Death stranding, Beat Saber, Astrobot, Moss, RE7 VR, Tetris Effect.

RDR2, TW3, Destiny, Destiny 2, BotW.

My favourite downloadable indie game.

This a very good thread. There have been a lot of distinctive titles that make this gen truly unique and I'll try my best to think of a few that capture my feelings in the most appropriate way.

- Killzone Shadow Fall -> This ...
- Infamous Second Son -> ... and this are the two games that made me curious about a PS4. These games sparked my interest and looked promising enough to make me believe that we've indeed entered a new era.
- Dead Rising 4: This ...
- Ryse - Son of Rome: ...and this are the two games for the Xbox camp that made me turn my head and made me believe that we've indeed entered a new gen.

And then came Mario Kart 8 and I bought it with Super Mario 3D World an Pikmin 3 and, boom, whatever Sony and Microsoft offered was completely irrelevant! My girl and I played these three games with a passion! The next gen started right at that point in May 2014 for us.

- The Order 1886: This game summed up perfectly for me what western developers thought of gaming in this gen: Just be pretty. Whatever you do, just be pretty! You can have the most boring and tedious generic cookie cutter gameplay but, for the sake of everything, try to look good at it!

Off topic: The Order 1886 really cemented the thought in me that gamers nowadays are all graphic whores throughout. I heard them all around me worshipping this game because it's sooooo pretty while completely ignoring the fact that it has super simple and boring gameplay. And I was like, is that what you really want?

However. These following games are just as much gen defining for me.

Games I own myself:

Nintendo Land
ZombiU
Donkey Kong Country: Tropical Freeze
Hyrule Warriors
Fire Emblem Awakening
Fire Emblem Fates
Metroid II: Samus Returns
Splatoon
Kirby: Planet Robobot
The Wonderful 101
The Legend of Zelda: A Link Between Worlds
Xenoblade Chronicles X

Games I've heard of but never played, yet still are defining:

Assassin's Creed Unity
Destiny
Street Fighter V
Resident Evil VII
Final Fantasy XV
Final Fantasy VII Remake
Metal Gear Solid V
The Witcher 3
Cuphead
Fortnite
Undertale

Halo Wars 2
Gears 5
Forza Motorsport 6
Forza Horizon 3
Killer Instinct (2013)
Hellblade
Grand Theft Auto V
The Outer Worlds
Alien Isolation
Hitman 2
Injustice 2
Mortal Kombat 11
Star Wars Jedi Fallen Order
Star Wars Squadrons
Fallout 4
The Evil Within 1
The Evil Within 2
Dishonored 2
Prey (2017)
Doom (2016)
Doom Eternal
Wolfenstein The New Order
Wolfenstein The New Colossus
Resident Evil 2 Remake
Resident Evil 7 (or Resident E7)
Ghost of Tsushima
The Witcher 3
Dragon Quest XI S
Streets of Rage 4
Sonic Mania
-
While i do have and played many Nintendo Switch games, but i can't mention them yet, Wii U and 3DS are all i can, based on i played long before i purged them my entire Wii U & 3DS collection:
Super Mario 3D World
Super Mario 3D Land
Luigi's Mansion 2
The legend of Zelda: A Link Between Worlds
Metroid II: Samus Returns
Splatoon
Donkey Kong Country: Tropical Freeze
Kid Icarus Uprising
Super Smash Bros. For Wii U & 3DS

Edit: oh fuck, it glitched. lmao!

Edit 2: There you go.

Breath of the Wild

This is what I dreamed "next gen" games would be like back in the 7th generation; complex, layered worlds full of interactive systems all woven together into an organic whole that allowed for awesome emergent gameplay. An endlessly wondrous experience through and through.

Splatoon

From its fresh and unique style to its amazing-feeling movement and mechanics, it was a real gem, plus also such a joy to see Nintendo go all in with a high quality new IP for the first time in a while. In a dark time for Nintendo, it was a beacon of hope.

Witcher 3

A rich and immersive world, satisfying combat, and stellar storytelling, but above all else just an superb sense of adventure that made dozens of hours fly by. There are few games I have managed to lose myself in so much as this one.

Doom 2016

Fantastic blend of old school sensibilities with modern technology, basically the definition of "badass". Proves you don't need gimmicks or checklists of genre tropes, just a core gameplay loop honed to perfection.

Hellblade

The most emotionally powerful experience I've ever had with a video game; an intensely poignant journey into the subject of mental illness backed up by excellent gameplay. A true work of interactive art.

Nintendo 3DS:
- Pokemon X/Y
- The Legend of Zelda: A Link Between Worlds
- Fire Emblem: Awakening
- Kid Icarus: Uprising
- Super Smash Bros. for 3DS

Wii U:
- Splatoon
- Super Mario 3D World
- Super Mario Maker
- Mario Kart 8

Nintendo Switch:
- The Legend of Zelda: Breath of the Wild
- Super Mario Odyssey
- Super Smash Bros. Ultimate
- Animal Crossing: New Horizons

PlayStation 4:
- God of War
- Uncharted 4: A Thief's End
- Marvel's Spider-Man
- Ghost of Tsushima
- The Last of Us Part 2

3rd Party:
- Persona 5
- Shovel Knight
- Shantae and the Pirate's Curse
- Ori and the Blind Forest
- Overwatch
- Fortnite
- Rocket League
- Red Dead Redemption 2
- Call of Duty: Black Ops 4
- Five Nights at Freddy's
- Cuphead
- Sonic Mania
- Kingdom Hearts 3
- Final Fantasy VII Remake

Nier: Automata 
MHW/Iceborne
Bloodborne
Uncharted4
Hollow Knight

If I were to name all the games I've loved this gen I would have name a lot more, however these 5 are the ones I'd consider "defining" of the gen for me.
I dont care to elaborate on my personal reasons tbh, anyone who has played these games already knows the quality behind them. 

This far into the thread and not a single person has said Nioh or Nioh 2. Honestly is quite sad. I will give my list later when I have more time, just had to interject.

God of War
Super Mario Odyssey
Uncharted 4: A Theif's End
Final Fantasy VII Remake
Persona 5
The Last of Us Part II
Diablo 3
Dragon Age Inquisition
Yakuza 0
The Last Guardian
Rocket League

Not all listed but yeah its been an interesting generation. I still rank most lower than 7th with more games played/enjoyed on the PS3/360 era, but these are the biggest standout titles that I've personally had a chance to play over the years. Here's hoping 9th gen deliver more for everyone!