Sonic The Hedgehog? Pure Genius.
Miles 'Tails' Prower? Super cute. Also Genius.
Knuckles the Echnida? Badass. Genius.
EVERY SINGLE CHARACTER AFTERWARDS? Idoitic.
If you actually look at how the events of the Sonic universe took place (eg time), Sonic actually met Amy Rose before he met Tails.
Dr. Eggman, Shadow, Rogue, E102-Gamma, Tikal, Big, and somewhat Cream/Cheese are respectable Sonic-related characters. Others like Blaze, Silver, etc, are the ones who should not have existed.