MEKA 0.32c - SMS, GG and Colecovision - DOS/WIN9x dosbox
MEKA by Zoop (main coding) and Hiro-Shi (Sound emulation) has been coded over the past 8 months or so and on its maiden release shocked quite a few people. Never before had the world seen such a fine first release, with a GUI to match. MEKA is fast, with the most accurate sound emulation yet and filled with Easter Eggs, like in-built games that start to function after a certain key/click combination. This release also adds COLECOVISION emulation to Meka.
BrSMS 1.21 - SMS, GG and Colecovision - DOS/WIN9x dosbox
BrSMS is right up there with MEKA, although it lacks the magnificent GUI that MEKA has. BrSMS is also very fast and has good sound emulation and has added Colecovision emulation in this release.
MASTERGEAR 1.2 - SMS and GG - WIN95/98/NT
MasterGear is made by Marat Fayzullin, who can be considered the "father of console emulation". MasterGear is another fine emulator but it is shareware and registering costs $35, more info is available here. It has to be said that ONLY the WIN32 version costs money, all other versions (unix/linux/freeBSD/etc) are free :)
MASSAGE 0.8f - SMS and GG - DOS/WIN9x dosbox
MASSAGE was king for a VERY long time, but is hadn't been updated for a long time. Recently James McKay (MASSAGE author), has announced that soon version 1.0 will be released. Although 0.8f is the last free version, version 0.9 has been released to registered users. Also, the source for MASSAGE 0.61 is freely available and can be downloaded here.
SMSFAN98 1.06 - SMS - WIN95/98/NT
SMSFAN98 is a cool SMS emulator that works like a charm, there's just one problem: It's in Japanese :) This emulator is worth the download though.
MGX 0.13 - GG - DOS/WIN9x/NT
MGX is a new Game Gear emulator by the author of Dboy, not much is know about it.
GGFAN PLUS 1.09 - GG - WIN95/98/NT
GGFAN PLUS is a cool GG emulator by the same author as SMSFAN98, Maechiko. This emulator is worth a download and it is also in Japanese.
Sega G3 1.11 (3rd) - SMS/GG/Mark3 - WIN95/98
This is the new version of GGFan and SMSFan, they have been merged.