Here are some sandboxes (playgrounds, sample sites, build your own class for free) to check out, in no particular order…
Blackboard Learn 9.1: http://www.coursesites.com/
Instructure Canvas: https://canvas.instructure.com/
rSmart Sakai: http://mysakai.rsmart.com/
Agilix BrainHoney: http://blog.brainhoney.com/free-account/
Pearson learningstudio (formerly eCollege and Fronter): http://www.pearsoncustom.com/pearson-learning-studio/requestdemo.php
Feel free to leave any other options in the comments and I’ll add them.