This is one of the "newer" ones that I really liked http://www.youtube.com/watch?v=l6IAoPAjzpw. It's the SWtOR one with all the Sith's. His whole speech is awesome. When he kills the first 3 guards then throws his saber to kill the others. Then when the saber swings back and he holstered it, it was so flood. When you see all the Jedi jump down and surround him you think "damn he's fCuked". Then at 1:48 your like "HELL YEA". If you don't get goosebumps at that part you have issues.
Also the 2010 E3 SWtOR one was really good to. http://www.youtube.com/watch?v=z0RuR3FREFw
Can't really say anything about this one. http://www.youtube.com/watch?v=Yvp3e1xqcnw&feature=related. Sephiroth is probably the most epic villain in anything that has ever been created.