FreezeSMS can emulate few platforms, Sega Master System is one of them. Actually, Sega Master is the main platform for this emulator. You are able to quick load you previous state, switch to full screen and many other options.

You can play your SMS games on this emulator too. Beside average functions it can make screenshots of gameplay and has advanced graphic setting like interpolation and VSync.

Gens Plus! Was originally created for Sega Genesis, but provides nice compatibility with Sega Master games. It also has wide range of video setting to make picture better even in full screen mode.