In this work an overview of current and future sustainable gas turbine technologies is presented. In particular, the various gas turbine technologies are described and compared. Emphasis has been given to the various advance cycles involving heat recovery from the gas turbine exhaust, such as, the gas to gas recuperation cycle, the combined cycle, the chemical recuperation cycle, the Cheng cycle, the humid air turbine cycle, etc. The thermodynamic characteristics of the various cycles are considered in order to establish their relative importance to future power generation markets. The combined cycle technology is now well established and offers superior to any of the competing gas turbine based systems, which are likely to be available in the medium term for large-scale power generation applications. In small-scale generation, less than 50 MWe, it is more cost effective to install a less complex power plant, due to the adverse effect of the economics of scale. Combined cycle plants in this power output range normally have higher specific investment costs and lower electrical efficiencies but also offer robust and reliable performance. Mixed air steam turbines (MAST) technologies are among the possible ways to improve the performance of gas turbine based power plants at feasible costs (e.g. peak load gas turbine plants).