string Array performance

In a method I am using following code.

       string[] Array1 =newstring[] {"Orange","Mango","welcome","power","Street","Visual"};

       string[] Array2 =newstring[] {"Orange","Mango","welcome"};

       string[] Array3 =newstring[] {"Orange","Mango", "power","Street" };

       string[] Array4 =newstring[] {"Orange","welcome","power","Street" };

I have total 4 arrays some items are repeating in the array. I want to take only the common items from all the array.

What is the best technique to improve the performance.