Well the games of my childhood, Total Annihilation and Seven Kingdoms, came out in '97. So for my own selfish reasons I would argue that the Pentium II is where progress should have stopped.

On the other hand, at least I'll get to play Castle of the Winds.

(I also loved Z: Steel Soldiers, but despite the '01 release date, I'm sure it too would have run on a Pentium II).