I use this in the computer lab, but you can adapt it for the regular classroom (provide dictionaries, for example.) It's about the reasons that make certain YouTube videos extremely popular. The TED talks are very useful, as you can activate the subtitles in English or in the language of your choice, and you also have the interactive transcript, which is very useful as well. You can even have the transcript translated into the language of your choice. But don't tell this to your students right away! ;) I hope this will be useful to you.