Hmm, this is a tough one. The first one that comes to mind is Final Fantasy, though they have been going downhill quite a bit recently. FF4, FF6, and FF7 have a powerful hold on my heart, and it will take quite a bit to pry the series out of there. Even if the mmo grindfest Final Fantasy games are giving it a good go.
If I had to put a second, it would be the Harvest Moon series. Specifically Rune Factory. I really do love those games, and it's kinda funny when you think about it: they were my first foray into anything remotely galgame like.