I have rather fond memories of using this while I was in high school (in the mid-to-late 90's). Considering that I didn't have a Mac at the time, it was one of the only ways I could play around with a real Mac (albeit a black and white one with an old version of the Mac OS).

The other options at the time were:

1) Shapeshifter, which ran on top of UAE (an Amiga emulator). It was basically unusable on a 486.

2) Executor, which was a clean room implementation of a 68K Mac. I probably spent the most time with this because it supported some reasonably recent programs and wasn't terribly slow.