I found all of IRON FIST except for 1 and 14 and did have to rely on eBay for those years later. 

While I'm fairly certain I'd have hated how dark and twisted the results would likely have been, DC's "Metropolis" line headed by Steve Gerber and Frank Miller might have produced some eye-opening moments. 

Similar in its potential to disturb and disrupt would have been Miller and Sienkiewicz's "Wonder Woman: Bondage" project. However it turned out, no doubt people would have been talking about it. 

The unproduced Rachel Summers "Phoenix" mini-series by Claremont and Leonardi would have been visually arresting, no doubt, as a Leonardi take on the world of "Days of Future Past" would have been a treat. 

Barry Windsor-Smith was said to have been working on a Thing mini-series that has been rumored to appear a couple of times here and there.

There was supposed to have been a "Superman 3-D" book done by JB in much the same vein as the Batman book he did, introducing a new villain for the Man of Steel called Tantrum.

The Uncanny X-Men/New Teen Titans #2 by Wolfman and Perez mentioned earlier upthread was to have featured the Hellfire Club and Brother Blood as its villains. That would have been something to see.

And of course, the Kirby "Prisoner" and Adam Hughes' Wonder Woman book remain treasures lost to the vagaries of fate.

Of course, Mr. Byrne is consistently right on the topic; replace Diana with Batman and ask if the story still works. Methinks it fails hard, whether it sells well or not.

I agree that the Metropolis line and the Miller/Sienkiewicz "Bondage" were likely to be sexually exploitative journeys into the fetishtic history of the character, tinged with a very modern level of violence and grime. 

When Kirby came over to DC, he asked what the company's lowest selling book was, so he would not be displacing a creative team who weren't already on their way out. He was told Jimmy Olsen, and that's why Darkseid, Morgan Edge, and the Fourth World all have their origins in that title. I have occasionally wondered what would have occurred had DC replied differently and Kirby has assumed control of Wonder Woman instead. The New Gods would likely have come in literally replacing the old and causing no end of chaos for the Amazons and Paradise Island. It is an image to conjure with.