Who is your favourite villain and who played the role?  

After watching the Dark Knight, i just looooovvvveeee the late Heath Ledger acts as the Joker. The role was so real, i never thought it was him. Just loved the movie, and may he rest in peace.

Yah I love Anthony Hopkins as Dr Hannibal Lecter and Heath Ledger as the Joker. I will also share my favorite villain of all time but I would not limit my selection to a human villain only since there are really villains in the movie that is not human at all.
I would start by Psycho's Norman Bates played by Anthony Perkins. The shy young and withdrawn men that is dominated by his mother. Then there was the Black Cape Masked wearing Darth Vader voiced by the baritone James Earl Jones. The Wicked Witch from Wizard of Oz played by Margaret Hamilton. The cruel Nurse Ratched in One Flew Over the Cuckoo's Nest played by Louise Fletcher. The pychopath Alex Forrest in Fatal Attraction played by Glen Close. Who could forget the possessed Regan Macneil in the Exorcist played by Linda Blair. The badass Alex de Large in A Clockwork Orange played by Malcom McDowell. The unforgiving Amon Goeth in Schindler's List played by Ralph Fiennes. The scary Jack Torrance in The Shining played by Jack Nicholson.The finger nails of Freddy Krueger in Nightmare on Elm Street played by Robert Englund...
Some of my favorite non-human villain character are the following: Alien from the Alien, The Shark from the Jaw, HAL 9000 from the 2001 Space Odysses. The Martians in the War of the Worlds,Gollum voiced by Andy Serkis in the Lord of the Rings.The Thing from the The Thing.Wew this is a long list..Better Stop :)
These are some of my favorite all time villain in the movies.

Yes, Anthony Hopkins was outstanding in that role. My favourite villain though is Dracula. I love the way Bela Lugosi played him in the 1930s and also how Christopher Lee played him later on. Dracula is an iconic role and these two actors were excellent in the part.