I have seen good-looking PS1 games, but I don't think I've ever seen a good-looking 3D PS1 game. Except maybe Final Fantasy Tactics, but that doesn't really count because it uses 2D sprites. Good looking PS1 games = Suikoden 1+2, Alundra, Brave Prove, Symphony of the Night, Mega Man 8 and X4-X6.
I have seen good-looking low-poly games, but they look nothing like PS1 games.