Sonic the Hedgehog Games

The Green Hill Zone
Series history, game zone descriptions and screens, character descriptions, and multimedia.
http://www.theghz.com/

NeoPortal Sonic
Offers screenshots of the games.
http://sonic.neoseeker.com/

Shadow of a Hedgehog
Images, music, and resources.
http://sonic.planets.gamespy.com/

The Sonic Center
Time Attack competitions and information.
http://www.soniccenter.org/

Sonic Dream
Contains information, secrets and glitches on Sonic Adventure. Fan art and fiction is also available.
http://www.angelfire.com/games3/sonicdream/index.html

The Sonic Foundation
News, information, music, art, and fiction.
http://www.sonicfoundation.org/

Sonic HQ
Contains information on the games, comics, cartoons, downloads, fan fiction, and music.
http://www.sonichq.org/

Sonic in Gr
Aimed at Greek Sonic players, though information is universal. Includes chat, cheats, and downloads.
http://sonic_in_gr.tripod.com/sonicingr/index.html

Sonic Metropolis
Game secrets, FAQs, music, and message boards.
http://wafonews.netfirms.com/neo-metro/

Sonic Oasis
Offers information, pictures, music, image galleries, and links.
http://www.geocities.com/shadow_da_hedgehog/

Sonic Online 2
Contains character profiles, history, and sprites.
http://www.soniconlinesquared.netfirms.com/

The Sonic Stadium
News, information, forums, and chat.
http://www.sonicstadium.org/

Sonic the Hedgehog Online Fun and Games
Offers sprites, images, and flash games.
http://www.dan-dare.org/Dan%20Sonic/Dan%20Sonic%20Hedgehog%20Gallery.htm

Sonic World
Background information on the games and cartoons. Offers MIDIs, fan art and other creations, and forum.
http://www.sonicworld.net/

Sonic X Network
Message board with off-topic, console, and character discussions.
http://s7.invisionfree.com/sonic_x_network/

Sonic Zone
Character bios and game data.
http://sonikku.com/

Sonicology
Prototypes, hacks, cheats, glitches and zone data.
http://sonicology.fateback.com/

Spacecolony ARK
Offers wallpaper, information, and screenshots.
http://spacecolony.sp.ohost.de