I can't say "definitive" but I would nominate the Valkyria Chronicles series as a new entry into the pantheon of classic RPG franchises. The first and second game were just so good and the gameplay is very fresh and somewhat deep.

It's hard to pinpoint something like this because there isn't anything as good as Final Fantasy that releases on the fast schedule that FFVII-X did. I would say Dragon Quest is still great, but they don't release them that often. The RPG classic has moved to handhelds and it seems more like smaller studios putting out one offs like Radiant History and some series who would fill the void left by Final Fantasy.