I'd say the timeless quality would be more apparent for someone who first played FF6 this year and still found it to be the greatest game. An old game "standing the test of time" for someone who played it long ago often just means looking through nostalgia tinted glasses.

Anyway. I would say it's a pretty decent mix. The truly exceptional games from old tend to remain in high spots, but other games I just like a lot tend to get pushed out by newer stuff. My favorites list is still largely dominated by PSX era despite that neither being the beginning of my gaming (which started with Atari and went through NES and SNES) nor all that recent. A few games from SNES era still cling to my top 10 or close but tend to get pushed down by newer games like Persona 5.