It's a tie. Two pieces that could not be more different from each other.
My favorite, the Gorilla spot for Milka from Juan Cabral, is a beautiful piece of advertising. I don't even know why I like it so much. The first time I saw it, I was exhilarated by the surprise of it, the weirdness of it, the rightness of it. At following viewings it grows more endearing, because you wait for his moment with the drumming gorilla. It is just delightful. As it promises, it is sheer joy, but it an unexpected, fresh way. It works in many levels because the song is cheesy (the kind of cheesy we might once have liked, though we wouldn't admit it in public), because what is a gorilla doing with a drum set, because it is iconic and ineffable and cool as hell. I love it.
The Halo campaign seems to me to appeal only to male geeks, which are legion. It is undoubtedly a beautiful commercial, with a wondrous use of music, but it's for a video game, for crying out loud.
There is something that deeply bothers me about the fact that the advertising cloaks the product in a mantle of righteousness that I find appalling. IT'S A VIOLENT VIDEO GAME. I think jurors were swayed by the wow factor, by the intricacy of the production. I don't hate the commercial, but I hate that it won.
If I had my druthers, I would have strongly considered the HBO campaign (TV only), instead. It is a brilliant idea, magnificently executed. It is the living, breathing embodiment of the brand. Seen on the big screen at the awards ceremony, it gave me goosebumps.