Siren. Seeing through the monster's eyes is fantastically cool. Hard game though. :-x

Also, Omikron. For having David Bowie in it.
Also the mix of Adventure, FPS, and Fighting games it.
Oh, and being able to take over other people's bodies when you die.

Phantasy Star, oh wow. Science fiction in an RPG, I'm sure no one would of thought of that without Sega.