With F-MDrive can design a vast range of sounds on top of 33000music instruments presets already available from Games VGMs. Out now! Windows 32-bit only (darn).
It looks like 8Bite PSG, a Master System sound engine is also coming soon
Youtube user Aly James is working on a VSTI for windows that emulates the Sega Genesis sound chip. So far it looks really fun and the sound is very good.