I havent played enough so my vote might be a bit bias or so and something majority of people would disagree but I had a hell of a time with Final Fantasy XV which is my most played PS4 game , my first platinum and I've enjoyed 120+ hours of it in a span of two and a half years.

Last of Us Part 2
Uncharted 4
Ghost of Tsushima
Dragon Quest 11
Persona 5 Royal
Resident Evil 7 (especially in VR)
God of War
Ratchet and Clank
Resident Evil 2 remake
Tales of Vesperia (didn't play the 360 version)

many more
What a great generation of games.

TLoU2. Easy pick.

I can't choose reliably right now (i.e. I might pick otherwise if asked again later), but it's probably between Assassin's Creed: Origins and Ghost of Tsushima, and right now, I'll have to go with Ghost of Tsushima. Both are flawed games, but at the same time, these are probably the games that had that special something among all the PS4 games I've played. Ghost of Tsushima feels better as a whole though, so that's the one I'm going with now.

The other notable contenders are probably Death Stranding and Metal Gear Solid V. Death Stranding was excellent and creative, but I feel like it lacked just enough to be able to rise above the rest. Metal Gear Solid V is probably the best stealth game ever made, but unfortunately it also feels like Kojima didn't have the resources to properly finish it, which hurts it.

Overall, it was a somewhat disappointing generation... or console, rather. Some of my all-time favourites, Grim Dawn and Cities: Skylines, were released during the PS4's lifetime, but I played them on PC and certainly wouldn't have enjoyed them as much on the PS4. But looking back at the PS3 and the PS4, I feel like the PS4 library felt lacking in a way the PS3 library didn't.

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Elden Ring.

I wasn't a big fan of this generation - not just the Playstation 4, but the XBOne, WiiU, 3DS and Vita as well. I probably had more fun playing 1080p/60fps versions of my favorite gen 7 games like the Bioshock and Uncharted collections than I did new gen 8 games. Still some good stuff though:

Favorite game: Uncharted 4
Best new IP: Horizon
Pleasantly surprising: Spider-Man
Biggest disappointments for me: GoW and TLOU2

I didn't own a PS4, but I have played many of its games on Switch and PS5, so I'd go with either Doom 2016/Eternal for being so epically badass, or Hellblade Senua's Sacrifice for being one of the most emotionally powerful video game experiences I've ever had.

Honourable mentions go to Witcher 3, Nier Automata, and 13 Sentinels: Aegis Rim.

There is so many PS4 games I need to play. Follow up games in my favorite series. I'm confident Resident Evil 4 Remake will take the top spot for me anyway, but The Last of us 2 and Uncharted 4 might stomp it.

P5 Royal