Mohandas Gandhi is a figure representative of an independence movement, which can perhaps be connected to nationalism. He worked to make India independent of England in the 20th century, using methods of non-violence resistance. 

I've always thought Adolph Hitler was the benchmark of nationalism.  Seeing pictures of the Hitler youth, to the marches, rallies, and even the way he used the Olympics to engender a sense of national pride always haunts me to a degree.  National symbols and propaganda were also a big part of his establishment of nationalism.

Fidel Castro is the classic example of a nationalist.  Even though he's considered by some to be a left-wing nationalist, he sought to unify Cuba by eradicating everything that he considered a pollutant to his country and people.  He adopted socialism as the only national political party. He took over control of all banks, industries, schools, hospitals, and doctors.  He also controls the press and any international affairs.  Since Castro came to power, Cuba's military prowess has considerably increased. 

By controlling all aspects of the lives of his people, Castro hopes to keep them in check and in submission to his regime. 

The leaders of North Korea (Kim Il Sung, Kim Jong Il, and now Kim Jong Un) have all used nationalism as a way of keeping their country together.  They claim a long and unbroken history for the Korean people and they argue that they are the only leaders capable of standing up for the Korean nation.