I think Nostalgia has alot to do with people thinking certain games are better than others. Ocarina Of Time is nostalgic for me, in a weird way it's the game that has made me who am I today. If it wasn't for Ocarina Of Time, I would have never had a website, would have never met any of you, and never found my fondness for working with computers.
I remember when it was storming outside really bad and I was playing the Forest Temple in OoT, and there really isn't anything memorable, I just remember playing that level while it was storming really bad one time.
But I feel like most people won't accept a game of today to take the place of games they have fond memories of. I think in 10 years (as that's how long it's been since OoT came out), that people might be more inclined to believe that GTA 4 is the best game of time, not that I'm saying I think it is however.