IDriveSafely and Comedy Driving were both miles better than GetDefensive. IDriveSafely was what I found to be the best so far as you could read most of the content, leaving you with extra time and just waiting. Comedy Driving was mostly videos so you had to pay attention most of the time. GetDefensive is horrible because it far exceeds the 6 hour minimum limit. The other two courses I've mentioned are easily completable in 6 hours.
Do not choose GetDefensive.