Although good, it definitely isn't the best Zelda game.
Visual quality: 10/10
To put it simply, this game looks amazing. From closer things that had great detail to the mosaic effect of places further away, I enjoyed how this game looked in every way. Zelda games usually prove that you don't need great graphical capabilities for a game to look great.
Sound: 9/10
The music in this game was just great. The music always fit the situation and didn't seem out of place. Even though most of the music won't go down as classics, I enjoyed listen to it.
The sound effect were good and never felt wrong or out of place, although there were some re-used sound effects.
Gameplay: 7.5/10
First of all, I really loved the new gameplay done with the sword. The sword controls were amazingly accurate with the slight error of a second unintended slash. Fighting enemies was both fun and challenging. Bosses felt right at home as well. Items felt so easy and natural to use even though the aiming controls didn't quite feel right.
However, even though the dungeons had interesting concepts, they felt small, simple, and far too easy. Except for one point, I never even had to think about what to do next, everything was right in front of you, making almost no challenge whatsoever. Each dungeon had about one or two small keys and felt very short and linear compared to previous Zelda game.
Side-quests aren't living up to other Zelda games either. Side-quests now feel few and unvaried, after doing most of the side-quests, I felt like I had done it all already
Story: 7.5/10
The story in Skyward Sword does present a few surprises like the red stone behind the old woman(avoiding spoilers, here) but, for the most part, the story is pretty predictable. It has an alright story, but I didn't ever see myself guessing what's next, being confused about a fact, or making theories about it.
Overall, I was impressed by the new things put into the game but what was expected to be in a Zelda game didn't feel up to par.