Best Dungeon: Has to be the Sand Ship. It was so diffrent from any dungeon from not only Skyward Sword but all of Zelda. I always loved dungeons like Forsaken Fortress simply for being unique. But it's not only the uniqueness that makes this dungeon. The design of the dungeon made it feel very real, when the ship was in ruins it really looked like it had been sitting for thousands of years. And then when you go back it made it look like a futuristic cruise ship. Also the puzzles were very challenging but were still fun, the ship was not too big so back tracking didn't bother me, and also the mini boss was great. The best part has to be for me going from the bottom of the ship while it is sinking and running to the top. It was just so epic. My only dissapointment was the boss. Sadly the boss was too easy and obvious that it might be my least favirote boss in all of Skyward Sword.
Worst Dungeon: The Ancient Cistern had a lot going for it but it fell very short for me. I loved the under ground and I loved the spider thread and other stories. But sadly the dungeon was easy, long, and had no real fun factor. The whole dungeon was based around the whip, and since the whip had a simple use of hitting levers that's pretty much all you do for the majority of the dungeon. And even though the under ground was creepy the puzzles were kind of pathetic and the underground contained mostly jumping on lily pads, swinging and pulling more levers. The Miniboss was a lot of fun and so was the boss. I would have preferred if the boss was harder but it's only a minor complaint since this boss was so much fun. The boss was the highlight of the dungeon for me, the design was amazing but gameplay wise it failed. Sorry Ancient Cistern but you are the worst dungeon.
Best Boss: The best has to be Demise. Even though many disliked this boss I loved it. I myself found it hard and it took a while for me to beat him. The background was great and the whole gameplay of the boss was great. Since we had to use Skyward Strike so many times in the game it seemed only fitting that you would use it against him.
Worst Boss: I have always been going bettween Tentalus and The Imprisoned. I had to pick Tentalus. The Imprisoned was very reptitive and slashing his toes felt silly the idea of having to get him before he reaches the temple. And even though he looked very weird the idea was good, maybe if you didn't have to fight him so many times people would like him better. But Tentalus was quick easy, and just plain boring. The tentacles through the the ship was ok but took too long too do. Then just aim shot and slash, BORING! Maybe if the Sandship was not as good of a dungeon maybe I wouldn't be as disappointing but I have to say he's the worst.