Great brief dialogues which make perfect practice if you want to polish your pronunciation and intonation in real life situations.

Elementary (A1)
http://www.oup.com/elt/global/products/headway/elementary/f_everydayenglish/


Intermediate (B1)
http://www.oup.com/elt/global/products/headway/intermediate/f_everydayenglish/


Advanced (B2)
http://www.oup.com/elt/global/products/headway/advanced/f_everydayenglish/