The one on the top right actually looks decently appealing, the one on the left looks okay as long as you don't look at his disturbingly large smile, and the one on the bottom right is a breached containment Keter class SCP.

It's the eyebrow angle. If it's not in a smug little V that makes you either want to think he's the coolest, smack the smirk right off his face, or possibly both, it's not Sonic.