Wire EDM is commonly used for machining of complex profiles in hard and exotic materials. In the present work the key performance of Wire EDM such as wire cutting speed, surface roughness and cut width in machining of three different aerospace class materials such as near beta titanium alloy, forged nickel base alloy and aged aluminum alloy are studied. Apart from electrical parameters, the wire with zinc coated brass and plain brass are used. TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) is the Multi-Criteria Decision-Making method used for selecting the best setting of control parameters. Parameter sets are ranked from best to worst based on the performance score. Zinc coated wire outperforms the brass wire almost for every response variable in case of Ni and Ti alloy while with Al it is as good as plain wire.