All 3.
PS4, PS4 Pro, Games I played most Rocket League, Minecraft, ESO, Borderland games.
Switch I've purchased 20 games for the device but have only played 3 of them. Mostly BotW.
Xbox One X, ESO also on this device, Currently playing Warhammer Chaosbane, PUB G was probably my favorite (hated the crashes though).

My all time favorite game across all devices, I do own this game on all 3 devices and on PS3 is Diablo 3.

All three of them

Switch:BOTW
PS4: Persona 5 royal
Xbox: Halo 5

Switch and PS4

Bonus
PS4: Undertale (but I played it first on PC).  Best exclusive is Spider-Man
Switch: Breath of the Wild with Puyo-Puyo Tetris being a close second

All 3 baby!

PS4: GOD...OF...WAR Sorry that is definitely my favorite PS4 game.

Switch: Between Mario Odyssey and Smash Ultimate

Xbox: Between Cuphead or Ori

PS4, Switch. Both OG models.

Bonus: God of War/Final Fantasy VII Remake (can't decide) and Super Mario Odyssey

PS4/Switch. I feel like I'd be missing out if I only had one of these.

I have so many games on each. Yakuza 0,Nier Automata/ are prob my fave games on PS4. Switch it's Xenoblade 2,Astral Chain and Daemon X Machina,Tales of Vesperia.

All three of them!

-PS4: Mega Man Legacy Collection

-Xbox One: Mega Man X Legacy Collection

-Switch: Mega Man Zero/ZX Legacy Collection

Only PS4 this gen after a good stretch of owning multiple home consoles.

Horizon: Zero Dawn. I wish I could experience it fresh from the beginning again. If my backlog wasn't so big, I'd probably play it on new game+

Switch and PS4 Pro specifically.

I don’t own any atm. But I have owned all three. The only one I would say had a favorite game for me would be Xbox One with “Killer Instinct”.