Find the Number With the Highest Sum of Neighbors
MATL, 20 15 13 12 bytes

t1Y6Z+tuX&gt;=)


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Explanation

t1Y6Z+tuX&gt;=)
t                  Duplicate the (implicit) input.
 1Y6               Push the array [0 1 0; 1 0 1; 0 1 0].
    Z+             Convolve with the input.
       uX&gt;         Get the maximum unique element...
      t   =        ... and compare elementwise.
           )       Index into the input.