I think the PS graphics engine became outdated quickly when compared with pc`s of course but the games are just as playable today as they were back then,i still have a PS set up and are playing Metal Gear Solid so i vote for the Playstation.
In my opinion the N64 only had a few good game titles and the anti-aliasing graphics engine it used lacked detail so it did not look good to me even back then,the Saturn has aged slightly better though its 3D engine is a little strange but the games are still decent.