The PSX has some great games, but yeah the 3D in a lot (even my fav - FF7) have not aged well AT all. But then again you play games for the gameplay, amirite?
Worst game graphically (3D category) has to go to a little known Japanese import known as "LSD - Living Sentient Dream" (at least I think that's the right title). Anyway it's essentially supposed to be... um, a dream. Full 3D first person... something game.
I don't even know if it's really a game, I spent most of the time walking around, hitting a wall (bookshelf? poster? .... refrigerator??? What IS that?) and being suddenly teleported to a weird dream cemetery/city that was devoid of any moving bits. You just walk around.
What a load of crap that 'game' is.