John I loved the Monopoly. I had most of those synths in real life for a long time. I started with the MS20 and expanded that with the MS50 to form a powerful modular with the step sequencer and vocoder etc. Then later Korg released those later models Monopoly included. You can make some very fat sounds by putting those oscillators into unison and stuff and detune them etc. It's got a lovely layout too enabling you to experiment with the sound. I loved the front panel on it.
I have heard the MS20 clones are fantastic too. I don't have the monopoly plugin although reading about you liking it has reminded me of it again. I think Korg are good people to model their own gear. They seemed to have done it well. I know that the Wavestation sounds amazing as the plugin. I had the real deal too and the plugin is a monster. It is a killer synth still now.
I have a real M1 and it is amazing how great it sounds. It can be released form its 80's/90 sound very easily. Just edit the reverbs and the chorus they often drowned the presets in and add a modern day effects processor and you have a completely different sounding animal. The M1 and the Roland JD800 have got lovely synth keyboard actions too. M1 being one of the best and nicest to play.