In this work, performances of Fixed Capacitor Thyristor Controlled Reactor, Static Synchronous Compensator, Thyristor Controlled Series Capacitor, Static Synchronous Series Compensator, Interline Power Flow Controller and Unified Power Flow Controller for power system stability enhancement and improvement of power transfer capability is analyzed. Behavior of a transmission system upon the addition of compensating devices is also studied. The changes in the behavior of the compensators for a change in their parameter values are then obtained and the best rating of compensators to deliver optimum results is found out. The simulation results demonstrate the improvement in the performance of the system for each of the above FACTS controller in terms of power profile and voltage stability. The results are then compared to determine the best controller for a given operating condition.