I think the ME-1 would be a great module, except I'm not sure if it is GM (general midi). Otherwise, the Kurzweil sounds are fantastic.
MY next choice would be any of the Roland sound mods (JV1010, 2020, SC55, 88, Edirol SD20 - 90, etc.) because they have a different timbre than the Yammys. I bought an SC88 on eBay for $200. AMS may still sell an EM100 GM sound module for about $60 - I have one of those too. Believe it or not, it has a Roland GM chip in it and does a great job for a little price and very little onboard control (AC,vol. MIDI in/out, mini stereo out).
Cass Pawlowski - Motown
PSR2000, SC88, Cakewalk
[This message has been edited by cassp (edited 05-25-2003).]