Ask HN: What are some good examples of true Single Page Applications?

I'm currently playing around with Clojure/Script and am trying to build a simple SPA. I think I finally get the high level concept of it, but then I realized I don't really know any website that feels like a true single page application... It would be really helpful to see what good examples of SPAs are out there, if any. Also any recommendations for other resources about the topic of building/designing single page applications would be greatly appreciated.