If you have not visited www.ted.com, or downloaded the app, please do so as soon as you can.  The site is full of inspirational, though-provoking videos on a plethora of topics.  Of course, it is always advisable to preview a video before you make it available to your students, but TED also includes interactive transcripts that you can skim for any objectionable content.  Larry Ferlazzo had a great post recently on his blog that included various resources to accompany the TED talks, including a wiki in which teachers share their ideas for using it in the classroom.