To provide some background... I commonly see it debated on the internet that Lenin is responsible for the deaths of thousands, that he was a corrupt tyrant, etc. Is their any historical legitimacy to these claims? And if not, what would you say to the people who make this claims?
Short answer: you're never going to get a general consensus on Lenin.
The guy undeniably instigated a Bolshevik authoritarian regime and, by all accounts, was probably going to continue as such. The thing which muddies Lenin's legacy is that he died fairly soon after his Bolshevik Communists took power in the revolution in 1917.
Lenin died in 1924 which was way before Communist power was consolidated, and this left a power vacuum. Stalin and Trotsky (Lenin's two main henchmen) fought for this power and tried to cast themselves as the legitimate heirs of Lenin and the Russian Revolution.
As you know Stalin won this fight and became the dictator of the Soviet Union. The divisive thing about Lenin is that he died before he could do anything more than overthrow the Russian emperors. Historians disagree whether he would have gone the Stalinist route and brutally subdued his rivals or would have attempted to build the egalitarian socialist utopia he had always proposed during his revolutionary days. Lenin is guilty of both these things. After an assassination attempt he instigated the "Red Terror", he built a powerful police state to kill those responsible. He also introduced the NEP (New Economic Policy) which helped the peasants of Russia grope towards a better standard of life.
Lenin is a bit like JFK or Jimi Hendrix in this regard. He accomplished great things and was a figure of mythology in his own lifetime but he merely set the stage for what was to come next, which was out of his control.
Like almost everyone, Lenin was shades of grey, it is impossible and intellectually idiotic to say: he was bad, or he was good. The only solution is to scrutinise his life and come to your own conclusions.
Source: Stalin: The Court of the Red Tsar, Simon Sebag-Montefiore.
Russia Under the Bolshevik Regime, Richard Pipes.
Not discouraging responses but here is a pretty good one here