Just finished it. Not only the best game in the series, but one of the best games I have ever played.
It's one of those games that only comes along once a decade or so and causes a complete paradigm shift for gaming as a medium. The way so many complex systems are woven together into such an organic, cohesive, and intuitive whole is pure genius. The level of interactivity and freedom makes pretty much all other open world games feel obsolete overnight, in the same way that games like Halo Combat Evolved and Mario 64 for their genres did back when they released. This is a watershed moment in gaming history.
Bravo, Nintendo. Bravo.