Welcome to the links page, it's a shame a few of these sites are dead now, I updated a bit and a lot of the links work now, and a few new places are up.

[M]

Sonic Sites

Sonic Stuff Research Group (dead, but still has a page)
Sonic Retro
Sonic The Webhog
Chris's Sonic Page (Dead link, one of the oldest Sonic sites)
The Sonic Team
The Miles Tails Prower Web Page
The Sonic The Hegehog Info Page
Blaze Jet Hegehogs Sonic World
Mads Sonic Page
The Emerald Starpost
The Sonic Fun Zone
A moment of Archice Sonic
Knuckles Haven
Sonic The Hegehog Area 51 (dead)
Emulation Zone
Dumb running Sonic Tumblr
Sonic Dream (Abandoned but still up)
Sonic Cult
ESPIOKaos.com (Midis!) (Gone)

Sonic Zone sites (to be updated later)

Casino Night Zone
Flying Battery Zone
Hidden Place (Zone)
Hill Top Zone
Sonic Metropolis (zone)
(The) Green Hill Zone
The Starlight Zone act 2
The Lava Reef Zone
Angel Island Zone