The generations system in III was amazing. I didn't care that the art wasn't top notch, I loved the game and seeing the story over three generations. Decades later I wound up making a storytelling game mostly based on it.
My favorite thing about 3 is that the soundtrack has tracks based on the number of characters in your party. Gain a character? Suddenly the music is richer. Lose someone? The music sounds more lonely.
Truly underrated game.