http://www.tubedubber.com/

The problem here is that the site's resources are limited. I tried dubbing the Metroid opening theme over the Alien opening sequence, but I couldn't find the former's original 8-bit rendition and the best I could find with the latter was all the series' openings one after the other, I think recorded from an admittedly steady handy-cam pointed at a TV screen. Oh, and there's no full-screen option, either.