I took iACT Globals "Mobile Application Development" course online via Skype. What I learnt there in few days, I couldnt learn in 2 months of self-teaching through various online methods. Now it takes me only few hours to make an Android app from scratch.
They have a well-defined system of teaching and doesnt teach random stuff at random time, which is quite professional compared to other online courses that I tried taking online. Their teaching staffs are definitely professionals in their field, and only teaches you what you will be applying in practical world, rather than handing out theoretical copies of the course.
It worked out pretty good for me, So I would recommend it to other people too. Also I heard a lot about their Six Sigma courses and so I am currently taking that course online, its about marketing and stuff related to bringing quality in the output from business.