I've compiled a set of my favorite presentations on Slideshare.net. I chose most of these presentations for their design - they follow good principles that avoid distractions and excessive text - rather than the content. The majority of these presentations don't have to do with education or presentation design, but they are great examples of how to design a great presentation.
I chose a couple of other presentations more for the content related to Brain Slides. This doesn't mean that their design is horrible by any means, but the content deals with how to make good presentations.
You can view the presentations below or search for them on Slideshare.