We use Desire2Learn. from what I have seen comparing moodle to D2L or even blackboard, is a bit like a space shuttle to a Cesena.
I went from a school that used Desire2Learn and switched to Blackboard and lost my hatred of Desire2Learn.
When I went to College we used WebCT. WebCT got swallowed by Blackboard. When I started working for that College we had just finished migrating to D2L. from my understanding its been seen as a vast improvement.
There's also the Clarion/Dokeos/Claroline line. About 5 years ago I had to decide on one LMS for a site, and I went with those ones (Dokeos a the time). It was simple but feature-complete enough to achieve what we wanted. To the teachers we showed Moodle, it felt like a big screen full of confusing buttons.