In our opinion, one of the best in the business at answering vegan questions and defending animal rights is Earthling Ed.
Earthling Ed spends time talking to people on the street about veganism and lessening their intake of meat and dairy products. This video is a really great one, that shows him come up against many of the common arguments against veganism.
The man he chats with is respectful and patient and hopefully inspired to change through the discussion. Enjoy.