Flesh is more economically viable. More of it, no need to crack skulls, easy to bite off when they're still alive. But I just couldn't resist the Return OTLD style "Braaaaaaaaaaains!"

Biting down into the flesh between the neck and shoulder would probably be pretty nice...and if I had the ability to remove it, the muscle that runs along either side of the spine.

Brains are yucky, I would go with blood and flesh if blood got scarce. However being fat I would probably be just as hungry as a zombie and just eat anything which got in my path, flesh, blood, dogs, cats, furniture, canary birds, books, computers, hamburgers anything. I would be one of those huge end bosses in zombie video games which just eat anything. :D

Everything, I'd just pig out, I'd end up like that huge disgusting mass of zombie in Monster Island that ate the zoo.

The we would both be mega zombies and we could have a epic fight over who got to eat whatever party of main characters stumbled into our lair. :D