This recreation of the famous (over three million plays on Nico) Idol Master Princess Bride MAD using Hatsune Miku and the other Vocaloids really caught my eye. Behold: Miku Miku Dance Princess Bride Trio!
Animation, music, all of high quality; the only possible complaint is that the encode quality (unfortunate) and 3D rendering (a limitation of the tool used) are on the rough side, but this is easily forgiven.
And the original Idol Master version: “Kotoko Princess Bride”
More irresistible dancing Miku.
If you fancy your own dancing Miku, start here.