Oh, and FM7 Sounds Vol. 1 (which is free with FM7 these days) is rather nifty; there are some impressive sounds there, either for use or disassembly/reverse-engineering (ah, so that's what you do with those tristate waveforms...) Even if a lot of them sound like an Instant VNV Nation Construction Kit or something. (Someone there obviously likes industrial music; hence all the "hard", "dark" sounds with names like "Eater of Souls" and "Mutilate" and such.)
FM7 is lots of fun, though a bit of a time-sink. One can spend lots of hours playing with it.