Just a small correction to the rather interesting WU about the Bengali language. The Mizo language is in fact called Lushai and does not use the Bengali script. It uses the Roman script and which is possibly a result of missionary activity in the region. (Mizoram is a state in the extreme north east of India populated mainly by tribals).
Further, the Assamese language while being largely similar in script to the Bengali one is not identical and has minor differences. But most Bengalis would be able to read Assamese with a fair degree of fluency.
Bengali has a rich heritage and its most famous author is Rabindranath Tagore, a Nobel Laureate, poet and novelist. Many of his poems have been put to tune and are known as Rabindrasangeet. Other famous Bengali authors include Sarat Chandra Chattopadhyay, Bibhuti Bhushan Bandopadhyay, Sunil Gangopadhyay and Sukumar Ray. The latter wrote mainly for children including a delightful collection of nursery rhymes called Abol Tabol and a fantasy tale called Hojoborolo. It is believed, somewhat controversially, that Steven Spielberg based E.T. on a character in one of Sukumar Ray's poems. His son Satyajit Ray was a noted film maker and won an Oscar for Lifetime Achievement.