First post, by m5215tx
After spendng some time with the ones that I have, I would say that the Yamaha MU2000EX is definitely my favorite. I have mine loaded with three PLG150 expansion cards but even without those I would still say it's the best sounding one that I own. I have the optical output going to a nice sound bar that I have and it sounds incredible. I was really amazed when I listened to the Final Fantasy 7 XG MIDI music. The Descent MIDI music (which is some of my favorite MIDI music) also sounds fantastic through this module. To be honest just about anything that I have played though the MU2000EX sounds great. I highly recommend getting one if you are a big fan of MIDI music.
The Roland SD90 would be the second most enjoyable one I listen to. It's puts out some great music so I am very happy to have one. It's expensive like the MU2000 but worth it in my opinion.
Of the older sound the modules, the Roland SC-55 and Yamaha TG300 stand out as excellent sounding units for their generation.
The most "unique" sound module that I have heard so far would be the Kawai GMega. That one sounds quite different from the other modules that I have heard. The MIDI music from Descent sounds different than most other modules but it's still enjoyable to listen to. The MIDI music from Dune is also unique but can sound a bit too far off for me. For example the Dune MIDI song "Arrakis" has a horrible sounding Shakuhachi instrument which ruins this song and the other songs that use it also. For the most part though its fun to hear how this module handles is MIDI music.
I just got in my Ketron SD2 and it made a big impression on me. It does not do too well with most of the Descent MIDI songs but the Dune and Dune II MIDI songs were incredible. It seems that MIDI songs that have a lot of traditional instrument use sound very good on this sound module. The SD2 is called the "Orchestral Wizard" so I guess that is why this is the case. At some point in the future I will be recording the Dune music from the SD2 and posting it on Youtube as I am sure others would enjoy listening to it. This may be a hefty claim but Doom and Doom II sound the best I have ever heard coming from the Ketron SD2.
Honorable mention to the Roland MT-32 and CM-32L for obvious reasons. Great sound modules for the games that support them.
Roland MT-32 (old), CM-32LN, SC-55, SC-88VL, MT-120, SD-35, SD-20, SD-80, SD-90
Yamaha TG100, TG300, MDF2, MU15, MU100, MU2000EX + PLG150-DR + PLG150-PF + PLG150-VL
KORG NS5R, X5DR