Here are my Top 10 Greatest Artists all time with their best painting (from my perspective).  As you can see, the list is heavily dominated by Russian Artists, who, in my opinion, were simply great.

I also focused on Artists who changed Art in a way it was never the same again, the prime example being Picasso, Klimt and Dali.

There are a couple of Indian artists that made the list: Vaikutam, simply the greatest abstract figurative artist, and Bapu, the greatest line artist:

Ilya Repin

Karl Brullov

Vasily Surikov or Ivan Aivazovsky

Rembrandt

William Waterhouse

Pablo Picasso

Gustav Klimt

Salvadore Dali

Vaikuntam

Bapu