Disclaimer: My idea of what constitutes the best of the 10th MMD Cup may not necessarily have much in common with the final rankings.
The first video today is unusual; a science fiction themed Sengoku Basara dance video. The video was made by the renowned Otthi who cites Tron, The Terminator and Call of Duty as reference material. Otthi is the person who originally made these Sengoku Basara models (as well as several others) and every video he/she makes using them tends to be worth watching. The music is HachioujiP's Hatsune Miku song 'Baby Maniacs'.
The next is a parody of the Btooom! anime opening 'No Pain, No Game', put together by Uta. It's well made even though I didn't like Btooom! much.
Another parody, this time of last year's Chouyaku Hyakunin Isshu Uta Koi anime. Even the lengthy end credits are fun to watch as user noi has posed the Sengoku Basara characters in real world settings.
Last but by no means least, users Tsurukame and Mog have come up with an incredibly high quality music video to the song 'Heart Beats' by emon(Tes.), here covered by singer Himawari. It features Yukimura and Sasuke; the detail in the effects and backgrounds has to be seen to be believed.