I own every single game on that list.

Sapphire was the first I owned, so I'll go with that. Although Alpha Sapphire is a darn good remake.

In terms of generations, it's close but III > IV > VI > V > I = II, because Fire Red and Leaf Green were great remakes too. My favourite games are Sapphire, Platinum and SoulSilver. But they're all flawless.

Hoenn >>>

I pretty much agree with all of this. Interesting simularities.

Sapp was my first owned too, but I adore Emerald as it's more polished and with the double battles. I voted it.

Definitely Crystal and Platinum!