She was such an inspiring actress and played many daring and controversial roles during her career.
I became a big fan of her acting after watching several of her more political / social "Parallel Cinema" / "Art house" films such as "Mirch Masala", "Bazaar", "Debshishu", etc
Later on in her career, she also acted in a few more mainstream Bollywood films like "Namak Halaal" where she co starred with Amitabh Bachchan, who took part in the book release event a few weeks ago.
You can also read a summary of her career here on Wikipedia.
In case you weren't aware, her son, Prateik Babbar, is also a talented actor and has played a wide variety of inspiring roles in his career already. My favorites of his include "Dhobi Ghat" and "Jaane Tu Ya Jaane Na" among others.
His latest film is called "Isaaq", and he's working on a Bengali film now entitled "Auroni Taukhon"