Robinson Crusoe is, quite frankly, a very exciting adventure story. There are sailing ships and stormy seas and a desert island and guns and cannibals and, well, basically a whole bunch of rollicking action in exotic and faraway places. Basically, it set a standard for all other adventure stories that followed.
Oh, and get this. Robinson Crusoe might have been based on the true story of a real-life castaway. His name was Alexander Selkirk, and he was a Scottish sailor who was stranded on his own desert island off the coast of Chile for four very long years. Selkirk was eventually rescued in 1709 and his story appeared in print and periodicals all over England. Did Defoe use him as the basis for his own Crusoe? Seems totally possible to us.