I think it would've been awesome if Misa had turned out to be a genius, and it was
her was taking advantage of
Light...
she could've become the leader of the new world. After all, she's portrayed as a stereotypical bimbo/model throughout the entire series...it would've been a great twist.
But overall, Death Note is one of the best animes of all time, and its storyline was effective, beautiful, and very well done.
(I was still unbelievably pissed when L and Mello were killed, though.

)