Me too - I like Standford Universities 'Historical Jesus'
I've taken a bunch but my absolute favorite was Dr. Robert Sapolsky's course on the brain. Completely fascinating. Another good one is Paul Bloom from Yale on ethics - half of the fun is listening to his accent! ;-)
I haven't taken any online classes but I've found some great history podcasts.
OK, I get it - you pay for these courses. I listen to podcasts via universities and museums through iTunes. I used to take Lynda.com courses which I paid for and can't recommend highly enough for the digitally challenged.