I'd post the video here, but I don't feel like I should. In my opinion, it's a PG-13 rating and that's getting too close to the line for my confort. So, I'll just add the link and warn you it has "bloody violence". I think it's sad and yet really, really awesome!!!! I can't seem to stop watching it... lol.
Japanese OP - TMNT - Same As It Never Was