Affiliate Sites.
Atani Software	Author of the multi-system Sega emulator, SegaEmu.  Sadly SegaEmu is now discontined, it is still available for download  though.
Eidolon's Inn	Home of the Genesis Game Guide, the G3O and Kega.  Why not visit the Tavern whilst your there, a good message board  for Sega/Genesis related topics.
Retro Base	Formerly Digital Relicts, a good G/MD site which also has  screenshots of every game.  Also covers Atari Jaguar & Lynx, Neo-Geo, SNES and the TG-16.
Sega Forever	An interesting Sega site with a few scanned manuals and guides for  Toejam & Earl and Streets of rage.

Emulation News Sites.
Vintage Gaming Network	Originally Dave's Video Games Classics and still one of the best  Emulation News sites out there. Updated several times a day.
Zophar's Domain	One of the oldest and best known Emu news sites on the 'net.  Has a links section to die for. Can't find something? then this is the  place to go!

Genesis Emulator Home Sites.
Generator (Dos)	Dos port of the fairly new G/MD emulator.
Gens Homepage	My favourite WinDoze based Genesis/Mega-CD/32X emulator.  Has a very high compatibility level and it's pretty fast too.  An essential download.
Kega Homepage	The other Win9x Gensis/Mega-CD/32X emulator by Steve Snake.  This is just as good as Gens, another essential download.
Megasis	A WinDoze based emulator from the land of the rising sun.  Thought to be a dead project until it was updated recently.
Sega Ages	Home page of the Sega Ages emulator by Quinntesson.  A new G/MD emulator which also has some early 32X and  MegaCD support.

Other Emulation Related Sites.
Retrocovers	Want some nice CD covers for your roms? Then this is the place to  go.