Wofano Wotanto
Hero
Cyberspace felt a bit rushed and undertested to me too, as well as being a somewhat belated attempt to jump on the cyberpunk bandwagon in the face of established competition. Striking cover though, I'll give it that.I've loved each system save Cyberspace (not well organized, poor fit, especially given CP2020 and Shadowrun)...
Thinking about things that used the RM/SM engine proper, my favorite ICE products were the Dark Space and Time Riders books, which I guess would be best described as setting books.
Dark Space was freaky science-fantasy with some Mythos-like elements, creepy biotech gear and weapons, and arcanotech interstellar travel. It stood out from the market pretty well at the time, although it never got any support and the last I looked it's one of the few ICE products you can't get in pdf.
Time Riders was a toolkit for doing time travel stories and campaigns in both RM and SM, had both magical/psionic and technological options for moving around in time, and had a lot of fairly system-agnostic advice on how to run the genre. Remains one of my favorite "how to do time travel RP" reference books of all time even with the GURPS and M&M books out there.