This excludes shit versions, country based, and new crap

Over all gold
But for first season blue

I prefer Generation I over II and Blue has Persian and a cheap Porygon, so that got my vote.

Blue, hands down.
I never got to play too much gold/silver, only beat it once and game is dead and never saves anymore QQ

Get a new battery.

red, no question

Crystal forever.

silver just cuz u got lugia with aeroblast

For first generation: Red
I like Venusaur as a starter "light years" more than the other two, and Zapdos is a by far my favorite bird. I don't advocate the use of more than one legendary, so from there Growlithe is the only choice IMO for a Fire pokemon. Growlithe can not be caught in Blue.

For second generation: Gold
Pretty much the same reasoning. Chickorita, Zapdos, Growlithe.

I'd say silver.