I love Mass Effect, Elder Scrolls, Grandia - the three stated above already. They're definitely the first ones to come to mind. They're all really different, too, so it's hard to compare them to each other in that regard. I think it'd be between the first two series for the one I'd be most hyped to play another game of, though.

I haven't played much of the Persona or Tales games, though, and I hear they are right up there. Just haven't grabbed my attention too much. Shoutout to Fable and Wild Arms for older games.