He is my favorite bolly director of all time. His movies are fresh, realistic and practical. I have watched most of his movies(except Bombay Velvet).
He started his career from a short film called "Last train to Mahakali"(available on youtube: https://youtube.com/watch?v=69VmIUhDgog).The film is amazing. The director was pursuing MBBS degree from Delhi where he watched "Bicycle Thieves" in a film festival and there and then decide a career in films. He left college and came to Mumbai, where he struggled and slept on footpaths. His brother Abhinav Kashayap gave him first break.
His talent was promising from the start and Star Plus was the first to notice that. He also gave dialogues and story, scripts for RGV films. He became famous from "Satya". He then made films like "Black Friday"(based on 1993 Mumbai bomb blasts), "That girl in yellow boots"(starring ex-wife, kalki koechlin), "Gangs of Wasseypur"(1 & 2, crime saga based in UP) and many more, all of which are box office success and positive critical reviews. He made DevD(modern day Devdas starring Abhay Deol) and Gulaal(political drama starring kay kay menon) in2009. After DevD he got a cult following. His only non-successful and negatively rated film till date is John Abrahim’s "No Smoking"(2007).
In 2014 he made "Ugly"(starring Ronit Roy) which is a thriller. He is also the founder of two film production companies: Anurag Kashyap Films and Phantom Films. To be honest, I only watch bollywood movies directed by him.