Songwriting
Technical ability
originality
attitude
image

I don't watch too many videos, so I have the image placed the last. I love an excellent song with a good text and musical composition, technical interpretation, some originality and attitude

Originality, - Because music could do with a brand new genre, none of this developing sub-genre crap, give me something i haven't heard before.
Songwritting, - can't write a song without good songwriting, well youcan, it just won't be much of a song.
Attitude, - without some sense of musical direction bands fall apart.
Technical Ability, - you can't be ****....unless your clit-45 ofcourse (hehe)
Image, - not really necessary, can help in some instances, lordi, gwar, kiss, twisted sister, etc.
but as long as your not repulsive and too fat to put on a stage performance what does it matter? it's the musical fusion you create is what really counts.