Any pair work books are great. I would be lost without them! We have gotten a few of them from Penguin and although they are expensive (in Korea anyway) they are well worth it and they have three different lessons and well as having ones for intant lessons and business and games. Basically they have lots of different ones. BTW it's English English, not American English. Here are some of the books.
http://www.amazon.co.uk/gp/search?se...%20WatcynJones
Where are you teaching?