What did Nicodemus recognize about Jesus that most Jews did not?

Nicodemus recognized that Jesus was a teacher come from God and that God was with Him, because no one could perform the miracles Jesus did unless God were with him. He understood the miracles were telling him something and that Jesus was someone special, a recognition most Jews did not have.

Les explains that Nicodemus came to Jesus by night and addressed Him as Rabbi, confessing, “We know that thou art a teacher come from God, for no man can do these miracles that thou doest, except God be with him.” Les points out that Nicodemus was head and shoulders above the concept of most of the Jews because he recognized the miracles were telling him something and knew Jesus was someone special. Jesus then answered that unless a person is born again—or, better, born from above—he cannot see the kingdom, showing that only believers enter.

John 3:2

The same came to Jesus by night, and said unto him, Rabbi, we know that thou art a teacher come from God: for no man can do these miracles that thou doest, except God be with him.

In what way did Nicodemus show he was different from most of the Jews?

Nicodemus came to Jesus by night and confessed that Jesus was a teacher come from God. Unlike most of the Jews, he recognized that the miracles proved God's presence, and he knew Jesus was someone special. He was head and shoulders above their concept.