A super-cute video with 'mochi' style Hideyoshi and Hanbee dancing alongside the popular 'mame' style Mitsunari! The song is Worlds End Dancehall by wowaka and the MMD video comes from user Mofu. I love watching their little feet move. The Toyotomi forces definitely need a proper reunion in the next game.
User Diggy-nao has choreographed a video to some of the 'shuffle' live voice performances by the seiyuu, where they play the part of different characters intentionally badly with comedic results. The video is hilarious in its own right and it also makes the skits easier to follow for people not familiar with the seiyuu. Ishino and Nakahara are amazing.
A more traditional MMD video next, with actual dancing. Aniki and Sasuke show off their moves to the song KiLLER LADY courtesy of the user Nayuta. I like the use of effects and facial expressions.
Finally, here's a MMD video which is gaining popularity thanks to its superbly sexy aesthetics. It's a Japanese-style PV put together by user SutiP and stars Japan and USA from Hetalia. The song is Jack's cover version of Iroha Uta.