I've often stated my belief, only half-jokingly, that Shin Megami Tensei, as a series, is everything that Final Fantasy wishes it could be, from a storytelling and character-building perspective. One of the most recent entries in that series, the spectacular Persona 4, is a great example - it's a lengthy tale (I spent 67 hours total completing it) but none of that time was spent poorly. The story is well paced, the characters are fleshed-out and likable, and the overall narrative is both easy to follow and intriguing in its twists. Persona 4 is, for my money, one of the best JRPG's of all time. It's the kind of game that I always thought Final Fantasy, deep down, wanted to be.
Final Fantasy XIII has shown me that I was wrong in this assessment. Because Persona 4 is still a game. If XIII is anything to go by, I'm not sure Final Fantasy wants to be that anymore.