This paper proposes a method for automatically determining which nodes in a given grid would have the largest contribution to an improvement of stability margins when wide-area control actions, in form of load changes, are applied to the nodes. The assessment of the influence each node in the grid has on the stability of the given generator is based on sensitivity analysis. The sensitivity of the stability criteria for aperiodic small signal angular stability to the corresponding change in the nodal admittances used to generate a prioritized candidate list over possible nodes for preventive counter measures application. The suggested method is tested on an 8 bus test system and IEEE 30 bus test system; the obtained results show that the proposed approach identifies the system nodes having the highest potential for improvement of critical stability margins.