Tyrion Lannister in Game of Thrones. There are a few moments I enjoy from him but two that come to mind are
1.) His "confession" in the Vale in order to get a "fair trial."
2.) Him making a private conversation to every person within the castle that he was going to send the princess of to a faction. He told every person a different faction because he knew one of them was a spy for the queen. When he presented himself to the queen whichever faction she discussed revealed the spy.
In terms of dialog... one that's short enough. That comes directly after that scene. This dialog is paraphrased and from the HBO series as opposed to the books.
Night time, a knight approaching a door. The knight speaks first.
T:"Yes ah, dear cousin."
K:"I hear that you have captured Grand Meister Pycelle. Release him immediately on orders of the queen."
T:"Why does the queen send you?"
K:"It is customary for you to ask stupid questions."
T:"It is urgent, yet she sends you and does not come herself, what am I to make of that?"
K:"I care not what you make of it. Do it or face treason."
T:"Do you usually wait long to carry out my sister's orders?"
K:"I carry out her orders as soon as they have been given to me as expediently as I am able."
T:"Then you must be a very trustworthy fellow to be invited into her chamber so late at night."
T:"You know she always loved lavender oil, even as a child."
K:"I AM A KNIGHT!"
T:"...an ANOINTED knight apparently."
T:"Do you think that my brother will be more likely or less likely to kill you after he finds out you've been sleeping with the queen."
K: "I would."
T: "My money is on more likely."
K: "It was all on her orders my lord I only served as I am able!"
T: "Oh no, a title, my sister's legs spread open for you on command! It was awful and just part of the duty. IS THAT WHAT YOU'LL HAVE ME BELIEVE!?"
K: "Mercy my lord! Mercy!"
T: "Save it for the king, he enjoys a good grovel!"
K: "I'll do anything my lord! Please spare me."
T: "Continue to pleasure my sister whenever she desires."
K: "My lord?"
T: "Remain within her graces, do all that she asks and more. But you will report to me every detail, everything that goes on with her. If I catch even a hint of betrayal your head will roll. Do you understand."
K: "Yes... completely... but Pycelle."
T: "...oh. Oh right, him. You can pick him up from the dungeons in the morning."
K: "My Lord?"
T: "I would claim I haven't harmed a hair on his head, but that, strictly speaking, wouldn't be true."
A personal favorite of mine:
"I wish we could talk honestly as two intelligent gentlemen."
"I wish that too."