One of my favourite things to teach is Business English.
There are so many interesting things happening in the business world that can be used in an ESL classroom.
TED talks in particular provide some great opportunities for vocabulary learning as well introducing some business concepts and ideas for discussion.
I like to use this one by Seth Godin in classes focusing on marketing - he brings up some good points about how marketing has changed, and what marketers can do to get their products noticed. And his ideas can be applied to other aspects of life as well.
He's a funny guy too.
Let me know what you think.