Well of course this is a popularity contest. That is what voting is about as opposed to a real sporting competition.

The only way to even attempt to quantify the best is to rate things by a categories (Art, sound, gameplay, etc) and then use a formula to weight the categories. But even then, who decides on the weighting and the formula? (Cause everyone will agree I am sure). It all comes down to opinion and is all very subjective.

As for higher seeded pins having an advantage being seeded against low ranking pins. Well duh? That is what seeding is about. Nobody wants to see the best go head to head in the first round. There is a reason that the top ranked pins remain in the top. However as time passes perhaps people will forget the old guard as fewer people will have played them.

You could group pins by decade of original release perhaps? It will always be hard to compare between generations. Was Gretzky better than Howe better than Ovechkin? It will always be opinion/popularity.