Radisson hotels are currently offering one free night when you stay two.
You need to check in on a Friday or Saturday (Thursday or Friday for hotels in Middle East) at participating Radisson Blu and Park Inn by Radisson hotels in Europe, the Middle East and Africa. The required promotional code when booking is WBUY2F2.
The offer applies to bookings made up to October 15, 2014 for stays from now until October 19, 2014.
Along similar lines, our favourite budget hotel, Premier Inn, is offering a free night to anyone who stays with them three times between 22 September 2014 and 31 January 2015. The free night can be redeemed on a Thursday, Friday, Saturday or Sunday for stays up to and including Thursday 26th February 2015.