The Pimsleur thing is a known scam, but Rosetta Stone is quite nice, i used it before with some success. The problem i have with college is that they need to beat that knowledge into everyone, even those unwilling to learn, or those unfit for higher education, and while i'm not questioning the quality, i do somewhat question efficiency, but if you have anything that may help, please feel free to post, i'll at least look at everything. I wish i could afford a private teacher.
I'm very aware that learning a new language can be something that may end up demanding a lifetime, though this strongly depends on your goals and definition of "learned", you've learned to speak your mothers tongue, but you are never going to be flawless, there just is no such thing, especially not with something that evolves so quickly like language does. Actually i think the Greek word for perfect is more of a "good enough", and i think that sums up pretty well how i look at it.