Also, to improve things, I would recommend a list of common tags.

"music video" might take up too many of those precious few characters allowed.
tv ad, ad, advert, commercial is there a better one?
cartoon, animation, stop-motion, flash, etc?
also, maybe a "classic" tag for the older been-around-the-internet stuff
music vs. music video
appropriate use of cool, crazy, weird, awesome, etc.
declaration that all crotch shot videos be tagged with AFV
nsfw also to be included in tag?
tv shows tagged as such
etc.