I'm not really one to gush about graphics all the time, as some people do. But if I had to pick one game for various systems that made me all googly-eyed.
Arcade-Streets of Rage 2
Computer-Bioshock, I have never played the computer version, but it is a computer game, even though it's on home consoles like Switch.
NES-Mike Tyson's Punch Out!
SNES-Secret of Mana
Sega Genesis-Ecco the Dolphin
GBA-Spyro: The Eternal Night
Wii-Okami
DS-Okamiden
Switch-Streets of Rage 4
Not including GB and GBC because I only own a handful via collections and eShop purchases, and feel I don't have a big enough sample to decide what looks great, what sucks, and what is average on the system. Can't think of any game I own on the 2DS that really blew my mind.