I've been using the LazyCam that comes with Mach3 (the registered version). When I have asked questions about it, I frequently get responses like "few of us use LazyCam" or "try xyz." The thing is, LazyCam seems to be working fairly decently.
I suppose I may progress to wanting something more sophisticated at some point.
One thing I really like about LazyCam is, I use an old notebook w/ parallel port to drive my small table-top CNC, it isn't very powerful and Mach3, LazyCam, and AutoSketch run just fine on it.
Anyone else out there using LazyCam with success?