Nes era: Final Fantasy II if I could have played it back then in English probably. Didn't really play rpgs until the ps1 outside of Pokémon though.

Snes era: would Pokémon count in this era? I'd say Pokémon Crystal if so. Otherwise, Chrono Trigger.

Ps1 era: Final fantasy viii. It was my first final fantasy and first rpg besides Pokémon. Got me into the genre.

PS2: Xenosaga

PS3 era: Xenoblade Chronicles