About two weeks ago, I bought 4 cd's and a booklet from "Living Language", it's about "Easy American Idioms"... I've been learning common American idioms there. And the book contains lots of dialogues as well, wherein the speakers really has great accent... I love listening to it over and over again. I gain accent faster than idiom knowledge from the program,
... It's really amazing. But if you're not quite into idioms, I think they also got "Basic English, Business English, Travel English..." You could choose what you think fits you well...