This question is so nebulous and unanswerable that it's absolutely pointless. Out of the hundreds of thousands of great games out there, you compile the options to 8? Okay, I understand that they are the 8 games usually referred to as the 'best games evar', and they're all fantastic games, but everyone will have a different favorite game (unless you're around the age of 13, then statistically you feel that Halo was forged by God himself).
My favorite game of all time is one-shot PS1 title Chrono Cross(usually regarded as a crime against nature because it's not a direct sequel to Chrono Trigger, which, let's face it, ended in a way that it needs no sequel). The game had fantastic graphics (for it's time), the cutscenes still look good today. It had a unique battle system, still mired in the familiar turn based system. A fantastic story with 11 different endings and dozens of characters leading to hundreds of parties.
Alright, I'm done ranting. Sorry bout that.