GENECYST x.xx - DOS/WIN9x dosbox
Genecyst is a product of Bloodlust Software, makers of the awesome NES emulator NESticle, Genecyst surprised EVERYONE with its awesome speed and even better sound emulation, the compatibility rate is phenomenal! The GUI is another fine Bloodlust product ;) Work on Genecyst has stopped, since the author is now working for a gaming company.
KGEN98 0.4b - DOS/WIN9x dosbox
KGEN98 is an emulator written by Steve Snake, a former Genesis programmer. KGEN98 boasts even better sound than Genecyst with the same speed. Sega used this emulator for release of the "Sega Smash Pack", which was an enhanced KGEN98 with a few games which you could buy. Can't go wrong with that, I suppose :)
MEGASIS 0.04- WIN95/98/NT
Megasis a new emulator written by a Japanese author. It's pretty cool, but the speed leaves something to be desired, you will need a fast PII to get fullspeed with this emu. Sound emulation is supported, but it is by no means complete. I guess this is one to watch out for.
VGEN 0.14 - DOS
Virtual Genesis is a new emulator, with good sound support and a fairly good compatibility rate. VGEN also has prelim Sega-CD support, but you will need the Sega-CD bios to run it. The Sega-CD part won't play any games btw.
DGEN 1.17 - WIN95/98/NT/2000
DGEN 1.04 - DOS - no sound
DGEN 1.17 - Source Code
Dgen is an emulator by Dave, author of DTMNT - the Teenage Mutant Ninja Turtles emulator. Dgen is a very good emulator, but it requires quite an hefty machine (PII) to run smoothly. We can expect frequent updates which is always a good thing ;)
Megadrive/Genesis Emulators