That depends who you are asking! If you speaking from a European point of view, the most important result of the Crusades would be the intellectual leaps made by coming in contact with the Islamic world. Remember that the Crusades took place during the "Dark Ages" where most scholarly activity was centered in monasteries or churches. The Muslim kingdoms, on the other hand, maintained a vibrant intellectual community with knowledge of geography, algebra, and the like. As more and more Europeans came in contact with these individuals, that information began to make its way back to Europe. Also, the main port cities in Europe, through which the Crusaders traveled, were those of Italy due to its close vicinity to Rome. This brought a great deal of wealth to the region. These two facets combined led Europe into the Renaissance.
