Web, Pronunciation scored poorly, Expensive, ★
Rosetta Stone teaches reading and listening, but does not emphasize speaking or pronunciation. It uses only the target language and pictures, so you can learn without distraction from your own language. It costs $200 for 3 months unlimited online, or $200 per level per language, which includes online oral sessions for 3 months.
The online demo does not score pronunciation, but the site and reviews (also here and here) say Rosetta Stone does score pronunciation, though they say it does not work well.
Speaking is also available in an online 50-minute oral session after each lesson, where you talk with a "coach" and "2 other learners with a maximum of 4." Here you can pick up the mispronunciations of the other 2-4 learners. Note you have limited months to use these sessions.
Like many courses it does not teach much grammar, unfortunate considering the price (FSI and Byki do teach grammar, and Pronunciator conjugates 100 verbs). Amazon reviewers are split, with criticisms of the lack of grammar teaching, limited vocabulary, limited support, and trouble reinstalling on a new computer.
The Economist magazine notes detailed issues with their teaching of Mandarin.