Just a PS4. God of War would be my favorite game for it with Bloodborne close behind.

I do how a gaming PC as well however.

I own all three but rarely play them.


Switch

Good: Zelda (duh), best controller of them all (the Pro controller, that is), short loading times.

Bad: A rather unimpressive library for my tastes (besides Nintendo titles), every peripheral and game is crazy-expensive.

Fav game: Zelda: BotW


Xbox One S

Good: Plays 4k Blu-ray, decent interface compared to the other two, great deals on older games via the online store.

Bad: Severe lack of properly competitive single-player games, massive online focus, extremely poor download speeds and intrusive and nagging features tied to online focus ("do you want to pay for Live? Despite never having played an online game on this machine ever? Do you? No? Sure? Really sure?").

Fav game: Forza Horizon 4


PS4

Good: Great library of single-player games, good game offerings through the Greatest Hits sales.

Bad: Even slower downloads than the Xbox, controller is mediocre at best and has the battery life of a ten-year-old electric car in the winter (in other words; shit), doesn't play Sony's own movie format 4k Blu-ray.

Fav game: Horizon Zero Dawn

All three.
As for favorite games:
Switch - Astral Chain
PS4 - Persona 5 Royal
Xbox One - Nier Automata

I own Switch and PS4.

Switch - Zelda:BOTW

PS4 - Probably Horizon, unless we're counting remasters, then Bioshock 1.

XB1 - Haven't played too many of their exclusives, so best thing for me is the 4k movie playback.  If I have to pick a game, then Bioshock 1 again.

I own all three, but I think this is the last gen that happens... they have been gathering increasing amounts of dust.... I just don’t have time to play games much anymore...I may just pick one for next gen or just stick with what I have...

I missed the bonus question; the best game on Switch is Zelda BOTW.

I personally own that one on Wii U though, so the best Switch game I actually own is probably either Hellblade: Senua's Sacrifice or Super Mario Odyssey; hard to pick between them, despite being so massively different both are absolutely superb.

Hard to pick a favorite out of so many different things, it's like having to pick either pizza or ice cream or something. The Last of Us(the original) was of course unforgettable, I played the remastered version. But I also enjoyed God of War very much and now who knows how much I'm gonna love Ghost of Tsushima..

I own all three
Favorite switch game is Breath of the Wild
Favorite Ps4 and Xbox one game is The Witcher 3(If you meant games not playable on both then Ratchet for ps4 and Gears 5 for xbox one)

Going by process of extrapolation, I guess I could say Hellblade is my top game for PS4 and Xbox One as well, since of the games I've played from those platforms on Switch its my favourite.