To learn Japanese? I've never used a program so I can't say, but I have heard good things about Rosetta. Those are several hundred dollars, though.
If you're interested in self-study, I'd recommend buying a textbook (there are a few I could recommend depending on your area of interest) that has a workbook and also a CD to do listening exercises. That won't do you much good in terms of getting speaking practice, and that's really something you'd need one-on-one work to get good at, but it would give you a good idea of basic grammar and vocabulary.
Are you near a university? Something you could consider as well is looking for a language partner, and it might be that you can find a Japanese student who could either do conversation practice with you for a fee or who might be willing to exchange language practice.
There are also tutoring services out there that can arrange services. I'm doing some work with one right now, though I can't say what I think of it quite yet. However hopefully the student I'm working with feels it's worth her while.
Options kind of depend on what your price range is, what your goals are, and how dedicated you are because learning a language, particularly something as different as Japanese, takes an awful lot of self-discipline.