I'll add the most obvious to the poll and if people have suggestions I'll edit them into the poll later. There is room for two more on the poll.

I'm gonna say Forbidden West. I've yet to play it on PS5 but even through YouTube compression, while I find myself doing comparisons towards other games, it never fails to look better. Even games designed for the PC, HFW looks better. It takes modded games and even a very modded RDR2 to beat it. God of War Ragnorok comes close but it lack something I can't put my finger on. I can't find any graphical mods for HFW to know if it's only beaten by itself in a modded form. 

The base PS5 version holds up with games that are heavily modded graphically. Some don't even reach the level of fidelity. The fidelity is so good that even on the highest end PC the base PS5 version  holds up with it. Some things like character models, clothing and hair look better on PS5 than PC. 

So far that I've experienced; Spider-Man 2

So far that I've experienced; Chrono Trigger

So far that I've experienced; PONG

From what I have played recently the visuals in RE4 remake are insane. Really impressive

Currently I'd say Warhammer 40K: Space Marine 2, but I have a good feeling S.T.A.L.K.E.R. 2 is going to take that title for me next week lol

Oh Good choice. 

Space Marine 2 looks great but it lacks something in the art department in the same way GoW Ragnorok does, TLC and attention to detail perhaps.... Idk what it is. STALKER 2 may well be the best looking game, now that looks insane. 

EDIT: Looked at STALKER 2 in motion and naaah, it doesn't hit it  Forbidden West Looks better. 

Agree on Horizon Forbidden West. It's the best looking game i've played so far. I think Ratchet and Clank Rift Apart also deserves a mention. Demon's souls looks amazing as well.

Edit: Also Hi-Fi Rush and Astrobot are very good looking games with a more cartoonish style.