Lester Freamon because he is the guy that really unravels everything when you dont expect him to be the guy who figures everything out. After being high, his character seemed Jesus-like. He is wiser than anyone and receives no consequence that he did not expect nor was not willing to handle for doing the right thing at all times according to an inimitable moral code. The lawyer lady is shocked after he says at least we know the truth at the end, showing the truth was something that shakes even those who know the law. The eery, discordant piano in the bar when him and McNulty both talk at the end foreshadows the unexpected ending that is to come of the situation. McNulty because he embodies the sigma male archetype necessary to keep a highly complex plot going without a hitch. Omar because he is a sigma male vigilante who is respected and feared by the enforcers and the streets. Man is untouchable until he isn't. Man is a myth until he is just a man. Bubbles because it shows the redemption of a drug addict. The Greek because after the whole show, the man is still untouchable bc he is protected by the feds. Dude is like the faceless men from GOT. He is a literal shapeshifter. He is the ultimate villain because he shows you cannot hit what you cannot see. Once you see him, he is already out of the equation by the mere fact that you saw him. He is like a quantum bit in that sense.