'A sahib in a dhoti', a 'bhadralok', 'a pragmatic patriarch','Communist by training and patrician in temperament, Marxist by conviction and a liberal democrat in practice, mass leader and recluse...' Just what or who was Jyoti basu?  As Ashok Mitra put it in the Telegraph:

After Subhas Chandra Bose, Jyoti Basu was the  next idol the Bengali masses created and clung  to. The chemistry at work was almost  inexplicable, for Jyoti Basu was by nature a  shy and reserved individual. That apart,  despite his fame as a spellbinding speaker, he  abhorred histrionics; his voice never deviated  from the normal pitch, the electric current  nonetheless hurtled across in waves and a bond  got instantly established between the person on  the podium and the assembled dishevelled rows  of humanity. The Communist Party of India  (Marxist) and the Left Front owe an immense  deal to this inexplicable phenomenon.

While most obituary writers recognised Jyoti Basu's biggest contribution to be the land reforms and agrarian rights for sharecroppers that he helped usher in via Operation Barga in the early years of  his tenure, there were also many controversies that dogged India's longest serving chief minister. Swapan Dasgupta, after characteristically saying, "If you seek his monument, look around,"  elaborated:

Initially, the party went in for radical land reforms and decentralisation of power to consolidate its hold in the countryside. But after five years, this strategy had run its course—though the political dividends keep flowing to this day. When it came to the revival of manufacturing and the creation of a new services sector, the Chief Minister found himself outvoted inside the party. His government adopted measures such as the abolition of English teaching till class 5 and the politicisation of institutions which set West Bengal behind by decades. Trade union militancy and crippling power cuts led to the decimation of small and medium industry. To the investing classes, Bengal became a big no-no. Its efficiency was limited to the organisation of bandhs.

...He inherited a crumbling edifice and bequeathed a similar structure to his predecessor. He merely prevented the roof from caving in.

Also See: Kanchan Gupta: Destroyer of West Bengal.  The Telegraph, Calcutta has a fuller list of the many controversies that dogged his tenure.

He had a reputation among reporters, as Monobina Gupta recalls, for his "exasperatingly short, brusque replies, sometimes even with outright sarcasm or rudeness". Which is why, it was wonderful to also be reminded about about the warm, human side of the man many people accused of being aloof:  Barun Ghosh on How Basu saved my job in Telegraph.

Some other articles of note:

Saubhik Chakrabarti in the Indian Express appraises Basu's failures and puts his tenure  in perspective:

Basu’s many obit writers, irrespective of their  politics, refer to him as a tall and visionary  leader who often seemed bigger than the party.  CPM’s Vajpayee, as it were.

Here’s the third surprise: Basu was actually  CPM’s Advani. He had personality by the spades.  But like Advani, Basu couldn’t rise above the  party. He didn’t even try. He was very much a  part of the party’s political think tank that  downgraded real welfare provisioning. He never  seemed to recognise the limitations of the  CPM-is-Bengal/Bengal-is-CPM mantra. Indeed, he  was its showpiece.

Jyoti Basu could have reworked the Bengal CPM  model. He had the political heft to do it. The  final surprise: he never saw the need.

Sunanda K. Datta-Ray in the Telegraph:

Given Indian class consciousness, villagers and  the party’s rank and file were awed by his  aloof manner and unseeing, hooded gaze. He  seemed born to rule. Westerners, especially the  British, loved his unsmiling visage and  clipped, monosyllabic replies. Society women  swooned over his gallantry. One who wanted her  whiskey small at a cocktail party was very  taken when Basu intervened, “Don’t worry, they  serve it in homeopathic doses in this house!”  Such repartee was not expected from an austere  Marxist whose government was identified with  radical social and economic measures

...He was too sophisticated to discuss land  concessions, contracts, loans and licences at  social occasions; but they soldered the bond  that gave rise to the “Communist Party of India  (Marwari)” joke about the CPI(M).

...He sanctioned or turned a blind eye to  criminally harsh repression and the use of  agents provocateurs. He chose to condone police  brutality, often making light of the atrocities  reported in the newspaper I edited.  “Editor-sahib sees torture everywhere!” he once  joked. When I defended my reporter’s  eye-witness account he replied that he had  asked the police commissioner, who had denied  the story. Naturally, the police commissioner  would deny a report that indicted his men.  Similarly, Basu did little or nothing to  prevent the CPI(M) and its allies from  sponsoring illegal immigration from Bangladesh.  He railed against the Anandabazar group at our  last meeting, saying they invented stories  about him.

Aditya Nigam in Kafila:

Basu was neither Bonaparte nor Caesar. He was certainly not a ‘heroic’ personality, and not by any means a demagogue. His political appeal came from his ‘ordinariness’. His political speeches in rallies at the Brigade Parade ground, were delivered in simple conversational style, almost sounding like one-to-one conversations. No fire-spouting rhetoric; no big words whose meaning only the converted can understand.

...Many have labelled this style ‘pragmatic’ – a euphemism for the somewhat more uncharitable term ‘opportunist’. That is to say, uncluttered by ‘ideology’. This diagnosis is, interestingly, shared by many. In the eyes of liberals, ‘ideology’ refers to doctrinairism and is essentially negative, whereas to many Marxists, it refers to purity. But for both, Basu’s style of doing politics shuns ideology. In our reckoning, both these readings are completely off the mark. Basu’s politics was certainly uncluttered by ideology but in another sense: there was nothing pre-determined about his responses. It was as if one was ‘thrown’ into a political context where all had to fall back upon was one’s political instincts.

Gopal Krishna Gandhi in the Telegraph:

It was in London, where I was working as  director of The Nehru Centre, that I had got to  know Jyotibabu. The year was 1993. The Nehru  Centre had organized a commemoration of the  200th year of Cornwallis’s Permanent  Settlement. Jyotibabu was the chief speaker.  His head buried in the text, he read in an  unfluctuating timbre and tone from a prepared  script. And as he progressed from page to page  of the closely typed document I could see many  in the audience ‘switching off’. Jyotibabu,  too, seemed to realize this for he suddenly  stopped midway and, looking up through his  spectacles, said, “You can see I am reading  this out. It has been written for me by an  expert who knows all these things. I do not  know all this myself. I am also learning as I  read this. You see, for most of my life I have  been among the people, with little time to read  or study….” The audience burst into applause in  appreciation of the candour of this man who had  shaped history, while most of the listeners had  only read history and some had written on  aspects of it.

Pratap Bhanu Mehta in the Indian Express:

Sometimes the true measure of a man is  precisely the sense of regret over all that he  could have achieved. Many analogies will be  used to describe Jyoti Basu. But with the  benefit of hindsight he reminds one more of  tragic Rajput princes more than anyone else.  These are people who built incredible political  citadels, often at great personal sacrifice.  They were even able to make them impregnable,  and often worked with a sense that they were  making history. The whirl of events, in the  world at large, did not defeat them. But it did  render them progressively more on the wrong  side of history.

Basu built a magnificent political citadel  against two enemies: the Congress centralism of  Delhi and the horrendous exploitation of share  croppers in Bengal. But while this was enough  to keep his party secure in power, it was not  enough to prepare his people for the whirlwind  changes that India and the world have  experienced. But it is a measure of his  personal greatness that his contributions to  Indian democracy will long survive debates over  his ideological fidelity to communism. Some  will regret that he was not more Maoist, more  ruthless; others will regret that he was not  Deng, more thoroughly pragmatist about  development. But Indian democracy will be  grateful that he remained Jyoti Basu: someone  who knew how to consolidate real power, but who  did not let it go to his head.