I would say EMS and E.K Nayanar, because in 1957 EMS began the first step toward the legendary Land Reform Act, he couldn't complete the mission and it was completely achieved in the time of E.K Nayanar govt in 1980 challenging all the odds .
Land reforms was the greatest event happened in the history of Kerala, there are lot many people to be credited, for example V.R krishnayyar who was the law minister during the EMS govt, he prepared the Laws for the act and Not to forget K.R Gauri amma, who was Revenue, Excise minister at that time.
At recent time it is V.S Achuthanandan , his hands are clean. Not a single allegation are leveled against him, he is corrupt free. He put his genuine effort to bring the culprits before the law.
There may flaws in his approach, after all he is a human, no other politician in the current scenario matches the legacy of the great freedom fighter, Stubborn Marxist.
The only allegation raised against him is that he is taking revenge on the opposition leaders. How could he take revenge,he has no personal rivalry with any one of them, he just took them to court on the basis of corrupt act they were involved when they were in power