HBO (ended 2008)
Any scene when McNulty and Stringer are shooting lightning at each other.
Like in the scene when McNulty arrests Avon but goes to Stringer and says "Catch you later."
Also those two courtroom scenes in the beginning and end of season 1, when they say to each other "well played." They are like two chess players, waiting for the other to go "checkmate."
It has to be the one where Rawls explains to McNaulty that, well, he is a reasonable guy.
Thing is, can't recall which episode actually has that scene. I'd be grateful if anyone could name it.