I've said it before I'll say it again: I don't consider Twilight Princess anywhere near the best Zelda game ever.
I have to be honest with everyone here...
I will agree that the game is far from perfect, the story is not as good as in other titles, it was too easy (especially the boss battles) and the gameplay is extremely familiar to OoT.
But to me the game truly shines because of the characters. Simply put TP has some of the most realized characters in the whole series, and perhaps the most memorable yet.
Link is far more expressive in this game than in any other game, rivaling Wind Waker. The characters are also expressive and very creative. Yeto, Yeta, Midna, Malo, Talo, Wolf Link, the Sages, the Gorons, the Bomb Shop keep in the end a lot of great characters.
It also has so many memorable moments. The howling moments were really awesome, same with the scenes in which Link trained with the deceased warrior.
The only thing I was annoyed with was the ending, simply because its the tired "And Link rode off into the sunset, adding yet another confusing element to the Zelda timeline" ending.
In fact, I would say the last half of the game is where it truly suffers. It has a great beginning and middle, but the end was somewhat weak and not as satisfying. Zant turned out to be a disappointing villain, especially since the first half of the game he is shown as this terrifying guy out to screw you.
In those aspects, I can agree why TP isn't the best. But to me, it has many enjoyable moments that keep it from being the worst.
Now if Zelda Wii is able to tighten up the story, add even more memorable moments, re-define the gameplay and work on the Zelda formula we could end up with Mario Galaxy equivalent of Zelda...