The Amazing Spider-Man (2012) has given us a grounded and realistic story and villain and the same will be for the next instalment, so no doubt we will see the ultimate version of the Green Goblin in this franchise.
In the ultimate comics, Norman discovered he had turned himself in to a demon like creature known as the Green Goblin after injecting an Oz serum containing his own blood to become a heighted version of himself. The effects of the Oz treated Norman's blood gave him the Ability to change to goblin form, greatly enhanced strength, enhanced durability, healing factor and is able to throw fire-balls. When he uses a smaller dosage it gives him green claws, horns and head, though the rest of him is human like in appearance. When Osborn overdoses on Oz, his horns, stature and muscles become larger and more powerful.
However he should also have a Goblin Glider to show his industrial and original side to his character, here is a great example of the Green Goblin that will fit well with The Amazing Spider-Man franchise:
http://www.comicvine.com/spider-man/4005-1443/forums/the-amazing-spider-man-2-speculations-750271/

Leave your comments and suggestions down below of what version of the Green Goblin you will like to see in future instalments of The Amazing Spider-Man.