Last but certainly not least, we speak of the most epic and evil of villains. (Agent) Smith has to be a personal favorite here, at Solve Unamusement, for the simple fact that he has a very systematic and well thought out (usually) manner which he does things. Compared to your average villain, bad guy, etc Smith keeps an almost positive air about himself. Pompous, some might say, but this is not a horrible thing for such a "person".
Smith is/was an Agent of the Matrix System which allowed him many powers beyond the norm. If you've seen the movies I need not explain and if you have not than you do not, rather have not, own(ed) a TV or any form of such entertainment for a few years. He's rather powerful and the most powerful being within the Matrix during the first film.