In 1974, we were treated to a two-page answer with some pretty cool results. Unfortunately, the color isn't the best in some of these alternates, but see what you think. Click on the picture to see the full size page.
So looking at this we see a few interesting options. The Scorpion is, of course, a Spider-Man villain. The Stingray became a Marvel hero in the 70's. The Owl was cool because Batman's evil counterpart from Earth 3 was Owlman. The last two...well, I guess you can say Iron Man was the last one. Shooting Star might have been original enough.
Of that group, I'd have to give The Owl the biggest chance of being a star. What do you think?