Hi Blackrock,
I'm an ESL university teacher in Tokyo, and have been doing it for 5 years. I've been using the free podcasts from
Free English lessons | ESL podcasts and the students really like them. What I do is get them to download the podcasts onto their mp3 players, and then the next day in class we listen together and discuss. I also print out the dialogue of the podcasts and get the students to act them out. Sometimes we just discuss the content. I've searched for a while and I think these podcasts are the most interesting and suitable for intermediate to advanced ESL learners.
Free English lessons | ESL podcasts