Have you taken either of the CS101 courses? Udacity's has already wrapped up and started a new 'hexamester' though Coursera's has just started. I prefer the Coursera lectures generally but with CS101 at least I think Udacity was much more engaging and challenging for beginners. So far the assignments on Coursera CS101 assignments feel pretty lackluster compared to the other classes (unless I've become unwittingly jaded, in which case I'd still like to hear what others think).