An excellent multiplatform emulator for Windows from KGen author Steve Snake. Emulation support:

• Sega Genesis
• Sega 32x
• Sega CD / CD+32x
• Sega Game Gear
• Sega Master System
• Sega Mega Drive

Genesis emulation is not inferior to Gens, and Sega CD and 32x emulation is simply unparalleled. It has all the standard settings, there is support for video filters (using Render Plugins, put the Plugins folder in the folder with the emulator).