What is your favorite Learning management system?

To all users and administrators of learning management systems!! Are you using Blackboard, Moodle, Claroline, Ilias, ATutor, D2L? What do you like/dislike about it? Does it work well for online learning? Which tools are your favorites? Instructors, do you feel the LMS enhances teaching? Or are there better tools for online or blended learning? 

I would be happy about any input of what you think!