Super Mario 3D Land
Man, there are a lot of tanooki tails in this game. On Mario, on Bowser, on Goombas, on Bullet Bills; it's downright silly. But 3D Land fully embraces this silliness, which forms part of its surprisingly unique personality.
Its general philosophy of level design is another facet of 3D Land's uniqueness; while the "NEW" Super Mario games are nostalgia-thick with modern twists, and the Super Mario Galaxy games are in motherfucking space, 3D Land's levels fit somewhere inbetween. There's a healthy mix of old and new powerups; there are some sidescrolling segments, but mostly three-dimensional geometry; there are even Galaxy-style throwbacks where props are made from enlarged pixel art, or a 3D Mario finds himself juxtaposed in a 2D scene from an NES game. The genuinely 3D perspective also allows for some cool levels which navigate on all three axes -- imagine a Galaxy level with more verticality.
On the other hand, since 3D Land is neither as nostalgically strong as NSMB, nor as epic and far-reaching as SMG, it really has its work cut out for it. So far the game has done pretty good at justifying the 3DS; but it's not as great at justifying itself, at least not so much as other recent Mario games have done. Its fresh take on the Mario formula is interesting, but not especially amazing. At least, not so far. I do have plenty of game left ahead of me.
Progress: Finished World 2