IGT (International Game Technology) is a true giant in the slots and gaming world. Established 1975 and was based in Reno Nevada the range of titles is huge and famous games include Cleopatra, Crown Of Egypt and Da Vinci Diamonds. It was acquired in 2015 by Gtech a London-based PLC formerly called Lottomatica and all these now appear under the IGT name. De Agostini are the majority shareholder. It is now known as IGT Plc.  A full catalogue of IGT slots and their RTP figures is here.