I voted Zell. Singleton is what he is and forever shall be. He established the floor, so to speak, in this business, and was a known quantity.
Zell comes into an industry in crisis looking to exploit, to bleed, to parcel off and to re-invent a valuable public trust without regard to anything but his bottom line. To me, it is the difference between a hyena that hunts its own food and a buzzard that swoops down on whatever's left of the carcasses. I respect the former just a little more. On the great scale of disrespect, of course.
With enough Zells coming into this industry, Singleton could have ended up looking good. If he didn't routinely outdo himself.