I've been using Rocket languages for about a year now, and am very satisfied.

The points system is a great motivator. (Let's be honest, we're all a bit competitive).

The "hear it, say it" functions really let's you test yourself and I think recently added "write it" completes it as a language course.

There has been some spelling mistakes throughout the course, but customer service listens and fixes anything brought to their attention.

I recently put the course (or my abilities) to the ultimate test, by traveling to a couple french speaking regions, and I surprised myself at how well it went.

Kudos to the developers of rocketfrench.