I would personally pick Amare over Dwight for a single game, but for the long run you bet your azz I would pick Howard. I still think he has yet to truely work on his mid-range game, but once he does (either due to declining athleticism or because he wants to be unstoppable) he will beast on people even more so then he does now.
I've only read the first page of the thread, (if you think I'm gonna go through 18 pages just to witness people's individual preferences then you is damn wrong, wrong like the plague!) however, I'll share my opinion and go with Dwight.
Much more consistent, much better defender, isn't injury prone and most importantly, IMO Dwight has a much higher ceiling than Amare. (in fact, Amare might have reached his peak) Not to mention their personalities - If you had to be a teammate with one of them, who would it be? Be honest. (on court ability aside) D12 is also a better role model as well as being a more positive light on his franchise than Amare will ever be.