Sonic

 Dark Sonic
 Sonic uses his anger to achieve this state, and possibly the energy from the hundreds of fake Chaos Emeralds around him. While in this state, Sonic shows his fury by destroying the two prototype Metarex that Black Narcissus pits against him in order to test his strength and speed.

 Super Sonic
 He usually has a greater impact on the story and is often part of the ending, or secret ending. Super Sonic has golden peach skin, golden spines and quills and red eyes. 
                                                        Sonic
 A blue and-peach-skinned, green-eyed, anthropomorphic hedgehog, who has the ability to move faster than the speed of sound and possesses the ability to curl up into a ball (like a regular hedgehog), primarily to attack enemies.                                                        

Hyper Sonic

Hyper Sonic has all the benefits of Super Sonic, such as invincibility, improved speed, and greater jumping abilities, but Hyper Sonic also has some improved abilities such as the ability to breathe underwater, further increased speed, power, and a double jump attack that will destroy all enemies within the direct vicinity, excluding bosses, and is referred to by some as "Sonic Boom" or a "Hyper Flash"