I've been trying to master a third language for almost 10 years now but because of work, school, kids, and life in general, I've been unable to do so. I did get to try a bunch of online resources though that were just amazing. Here are some in case you're trying to learn these languages:
http://talktomeinkorean.com/ - Free
https://www.learn-korean.net/# - Free
http://oli.cmu.edu/courses/all-oli-courses/french-i-course-details - Used to be free, now only the sample is
http://www.bbc.co.uk/languages/french/ - Free
I also tried a lot of audiobooks and found Michel Thomas to be the best for both French and Spanish.
What are the best sites you've tried and for what language?