Sam - I hope you don’t mind - I moved your list of resources to the top post and converted it to a wiki. It seems like a great resource that we can all maintain.
Useful resources. In addition, we probably all build some of our own based on specific needs. For instance, put together a bunch of example scripts in a Markdown document, in French, for a presentation in a college course. Did other presentations for workshops. @Martin has at least one video presentation, somewhere, which shows a lot of what you can do with Sonic Pi.
Something which interests me a lot is how people conduct classroom activities around SPi. In my experience, guiding people through the embedded tutorial, answering contextual questions and providing personalized advice has been quite effective. Especially with younger learners. Adult learners may need a bit more guidance, as they have to go over the hurdle of what they already think about music on computers. Several of them keep wanting to compare with other approaches instead of just playing with the code and having fun with it. Giving them a very clear orientation may help, especially if they perceive the uniqueness of the approach.
Apart of the embedded tutorial, are there resources which have been updated to the full I/O we now have? Didn’t yet get an opportunity to use SP3 in a workshop but my sense is that it’s a real game changer. Getting people to create a simple synth and play with a controller is a much easier way to get some people involved than following instructions.