It has to be Shadow of the Beast.
Technically, it was a groundbreaking game in its day, and I still think it looks good today.
Compare a lot of the early Playstation stuff with later games, and they don't hold the attention so well.
Its ironic. Either SOTB is a testament to Reflections and Psygnosis's skill at developing software, or an indicament that few others managed to match Beasts technical ability in such jaw dropping fashion.