Adam Ford's Stability Ball Abs or Core (I think the updated version is called 'core.' It's available at Amazon. There are three levels, and the 'advanced' level really is! You can also make the first two levels tougher by doing the advanced moves he does on the second round, during the first round as well.
A bonus: Adam does the workout shirtless, in some cute boxer-over-brief shorts, and he's one fine-looking man....just from a 'being able to see the muscle at work' standpoint, of course, LOL!;-)
I agree that Tracey Staehle's core workout is excellent, but it's very long. I asked Tracey about how to shorten it, and she was going to post some ideas (but I haven't checked back for a while I actually felt some spinal erector and other stabilizing back muscles work that I *thought* were strong before. The most useful part may actually be the first segment, with a balance of ab and back exercises, so you can play around with it and shorten it). Her cuing and form pointers are excellent, and she goes for precision in movement rather than big moves for show.
"3-D" abs looks intriguing (it's also at Amazon), but I haven't seen or tried it, so I can't recommend for or against.
I think Cathe's ab work in BMax2 (the bonus stability ball work--is that the workout it's on? or is it Butts and Guts?) is very good.
I don't reach for Core Max much, and it has been on and off my 'get rid of" pile a couple of times. Too much ab, not enough 'core,' and some moves I frankly don't see the benefit of (the rocket shoots done that way use too much momentum...they must if Cathe feels it's necessary to stretch the triceps after doing them).
