Well, 2nd gen has lots of good things, for example: wouldn't it be great to see a Suicune running on a tropical beach??
But the 1st one is much better... reasons: Charizard, Arcanine, Blastoise, Snorlax, Lapras, Mewtwo, Zapdos, Dewgong, Aerodactyl, Dratini-Dragonair-Dragonite, ivysaur, etc.