Why so serious, son?

The villain is the life of the film. If the villain is not strong enough film will fall flat. Take Sholay if Gabbar was not the menacing and terrifying sholay wouldn't have been Sholay.

Gabbar, Dr.Dang and Mogambo have been top 3 villain of Bollywood for long time now. Sadly, bollywood films have hardly created any villain who will be of the same league as these three. The advent of Yash Chopra love stories and then Karan Johar and company carrying the baton villains in Bollywood saw a dormant period for too long.

Hopefully with emergence of new directors sooner or later we will see a villain who will terrify us as Gabbar did. Till then lets look outside Bollywood and list down villains who can give us nightmares

Joker - The Dark Knight Rises - Heath Ledger

Knife between the lips, and the knife in Joker's hand - Joker with scars on his face telling the story how his father gave him those scars. Now that's terrifying. 

Heath Ledger's Joker - unpredictable, dangerous, as menacing as Gabbar. He is right up there.

Calvin Candie - Django Unchained - Leonardo Dicaprio 

A plantation owner who is ruthless when it comes to business, earning profit. He forces his slave to fight to the death in boxing matches called Mandingo fights. He doesn't shudder with those gory fights or sight of blood.

Colonel Hans Landa - Christoph Waltz - Inglorious Basterds

His job is to find Jews in hiding. He is calm and very mechanical about his job. He genuinely believes that Jews are ought to be killed. He takes his title seriously "The Jew hunter" and likes it a lot.

Li'l Ze - City of God 

Li'l Ze is more like Joker - unpredictable, psychotic. He doesn't even wink an eye before shooting 7 year old kid's foot. As 10 year old he loots a motel and kills dozens of people. He enjoys killing and helplessness of his enemy.

Amon Goeth - Schindler's List - Ralph Finesse

The SS officer incharge of a concentration camp who shoots Jew for target practice. You can see hatred for Jews in his eyes. He can't stand that any Jew can be superior to his race. He shoots a Jewish female engineer when she says that the way they are building a house is wrong. After murdering her he orders his soldiers to get it rebuild the way she explained.

There might be many more who I must have missed out. But these are the top 5 (not necessarily in that order) that I remember. 

Let me know what you think about it.