I'm not sure how many people of this site follow mixed martial arts or its roots, but if you do, Kazushi Sakuraba and his anime antics are no stranger to you. In my eyes Saku is the probably the greatest fighter of all time, his blend of pro-wrestling antics, and anti ju-jitsu grappling really catapulted MMA to where it is now. Saku is also a huge otaku, and his latest public training video shows it.
There's a couple other awesome videos after the jump, courtesy of Crunchyroll. If you aren't familiar with the Gracie Hunter's fights, do yourself a video and get some knowledge on YouTube. Make sure to support Sakuraba is his upcoming his bout at Dream 17.
Kamen Rider entrance
Neon Genesis Evangelion entrance
From other sites around the web