If we are speaking of "contributions" in a positive sense there are only a very few things that Louis XIV did that could truly be seen as positives.
Louis's court was responsible for a great deal of artistic accomplishment. For example, ballet was refined and formalized at his court and the first ever ballet company was formed in France during his reign. The arts patronized by Louis set the standards for European society at the time and can be seen as a major contribution of his.
One can also argue that Louis contributed to Europe by centralizing power in himself. This might be seen as a bit of a dubious argument, but you can argue that Louis reduced the power of the aristocracy, giving it instead to ministers who were appointed more on merit than on birth. It is hard to say that centralizing power was great, but taking power away from aristocrats might be seen as a contribution.
Arguably, Louis's most important contribution was to create the sorts of conditions that led to the French Revolution. Obviously, Louis had no intention of creating such a legacy, and the revolution did not happen for a long time after his death. But it is arguable, at least, that his reign set the stage for the huge changes that happened in Europe as a result of the French Revolution.