From The Cutting Room Floor

Sega's answer to Mario (well, the second answer, anyway), this attitude-laden speedster has been everywhere, in terms of genres, quality levels and - since the Dreamcast died - consoles.

The Sonic the Hedgehog series
Sega Genesis	Sonic the Hedgehog • Sonic the Hedgehog 2 (Prototypes) • Sonic the Hedgehog 3 • Sonic & Knuckles (Prototypes) Sonic 3 & Knuckles • Sonic 3D Blast (Prototypes) • Sonic Spinball (Prototype) Dr. Robotnik's Mean Bean Machine • Sonic Classics
Master System	Sonic the Hedgehog • Sonic the Hedgehog 2 • Sonic's Edusoft • Sonic Spinball • Sonic Blast Dr. Robotnik's Mean Bean Machine
Game Gear	Sonic the Hedgehog • Sonic the Hedgehog 2 • Sonic Chaos • Sonic Triple Trouble Sonic Labyrinth • Sonic Blast • Sonic Spinball Dr. Robotnik's Mean Bean Machine • Tails' Sky Patrol • Tails Adventures
Arcade	SegaSonic the Hedgehog • Sonic the Fighters
Sega CD	Sonic CD (Prototypes‎)
32X	Knuckles' Chaotix (Prototypes)
PC	Sonic's Schoolhouse • Sonic & Knuckles Collection • Sonic 3D Blast • Sonic CD (1996, 2011) Sonic the Hedgehog 4: Episode II • Sonic Generations • Sonic Adventure DX • Sonic Adventure 2 • Sonic Heroes
Saturn	Sonic Jam
Dreamcast	Sonic Adventure • Sonic Adventure 2
Neo Geo Pocket Color	Sonic Pocket Adventure
GameCube	Sonic Adventure 2: Battle • Sonic Heroes (Prototypes) • Shadow the Hedgehog Sonic Mega Collection • Sonic Gems Collection
Game Boy Advance	Sonic Advance • Sonic Advance 2 • Sonic Advance 3 • Sonic the Hedgehog Genesis
PlayStation 2	Sonic Heroes
Xbox	Sonic Heroes
Nintendo DS	Sonic Rush (Prototype) • Sonic Chronicles: The Dark Brotherhood Sonic & SEGA All-Stars Racing
Wii	Sonic Colors • Mario & Sonic at the Olympic Games (2007, London 2012)
Xbox 360	Sonic the Hedgehog • Sonic Unleashed • Sonic Generations (Prototypes) • Sonic Adventure 2
PlayStation 3	Sonic Adventure 2
PSP	Sonic Rivals
J2ME	Sonic the Hedgehog Mobile • Sonic Jump
iOS	Sonic the Hedgehog (2013) • Sonic CD Sonic Jump