Single Status Update
When you think about it, Amy in the pre-Unleashed era was honestly one of the more influential characters, even if her role wasn't always combat orientated. Sonic and the more combat oriented people might be the big faces of the band so to speak, but in many ways she was the one who often times noticed or helped out in the small but important ways that others overlooked.
Take Gamma for instance: A machine who blindly followed orders no matter what, proving himself to be the best of Eggman's robotic soldiers at the time, but harboring doubts when he saw Eggman's callousness towards his fellow machines who had failed.
She managed to influence Gamma to start doubting Eggman and was brave enough to stand against Sonic despite him wanted to destroy Gamma, thus allowing for Gamma to not only turn against Eggman despite his limited programming, but also drive him to destroy several of Eggman's strongest soldiers at the time and free his trapped Flicky family.
Shadow was a grief-stricken revenge minded person, driven only by distorted memories of his past and friend, and a desire to punish humanity for destroying his life.
She managed to get through Shadow's memory block in Sonic Adventure 2 where no one else was able to and convince him of the error of his actions and the true intentions of his dead friend, not only allowing for the world to be saved from Gerald's revenge beyond the grave, but also in the long term ensured a permanent new ally in the fight against evil.
Silver was a well-intended, but sadly gullible pawn who was so desperate for the salvation of his future, that he was mislead by evil into nearly ensuring a far worse future for everyone. Yet deep down he harbored doubts of his mission, but did not see any reason to change since he believed it was what needed to be done, even if unpleasant.
She was able to plant the seeds of doubt in Silver's mind in the erased 06 continuity by defending Sonic from him despite the drastic power difference, and made him start questioning his actions working for Mephiles, thus ensuring that in the long term he would be able to help put an end to the threat of Solaris.
She's not the best fighter, and her bratty moments and obsession with Sonic does get in her way at times, but when the chips were down, she often times ended up being a more important catalyst for change for several of the most prominent characters in the franchise than any amount of the flashy kickassery of her larger than life friends, and did so primarily through her smaller actions of being an honest and kind soul.