Notes:

Sonic's best friends throw him a surprise party

From left to right:

Charmy Bee: Annoying kid that's part of the Chaotix detective agency
Miles "Tails" Prower: Sonic's best friend and adopted little brother
Espio the Chameleon: Ninja that's part of Team Chaotix
Rouge the Bat: Jewel thief and government agent
Vector the Crocodile: Leader of Team Chaotix
Knuckles the Echidna: Guardian of the Master Emerald who doesn't actually guard it anymore
Blaze the Cat: Princess from another dimension and guardian of the Sol Emeralds. Has pyrokinesis and the amazing ability to keep up with Sonic in high heels.
Amy Rose: Annoying 12 year old who wants to be Sonic's girlfriend
Cream the Rabbit: Polite young girl