The difference between Stalinism and Fascism is pretty thin, actually. The only real difference is that Stalin claimed to be communist. The EU and other human rights advocates consider them roughly comparable.
The differences are actually huge, especially in that fascist economic policy has more than a snowball's chance in Hell of actually functioning. Fascists are very pro-corporate and pro-private property, so long as the corporations and property serve the interests of the State and what the State believes to be in the interests of the well-being of their people*. The fascist economic model is founded in state capitalism, which has proven to be very successful in modern China and also Libya, before the war broke everything in the latter. Marxist-Leninist economic policy, on the other hand, is a total fucking basket case that inevitably results in famine when implemented.
In a nutshell, fascism isn't nice but it works, which is the highest praise I will give it. Marxist-Leninism is even less nice and has nothing to show for it other than a death toll that made the Nazis** look tame in comparison***.
*And their people alone, of course.
**National Socialism is related to, but distinct from fascism.
***I'm lumping Maoism in here as well, since it was very similar in theory, practice, and results.
Edit: As for social policy, there are even more differences. Fascism and national socialism lean towards jobs programs, charity****, and family subsidies while Marxist-Leninism supports universal welfare. Both fascism and Marxist-Leninism also have tendencies of suppressing or altering history that disagrees with the line of the ruling party, but I would argue that Marxist-Leninism has a much worse history in that regard, since it seeks to erase the past entirely, while fascism seeks to cherish and appreciate it... so long as it supports the will of the State, of course.
Not all totalitarian regimes are alike.
****That said, National Socialist "charity" drives were effectively mandatory. It was seen as one's civic duty, and you risked being chased and beaten by an angry mob or even "disappeared" if you failed to donate enough food and clothing to the poor. An old pair of boots and a pot of stew a year would not do.