Legacy of the May 1968 Paris riots

Did the uprisings of May 1968 in Paris over student tuition fees mark the end of a trend of uprisings?

No, absolutely not. Then end of a trend of uprisings was la Commune de Paris, or perhaps even the French revolution of 1848. With the latter stopped the tendency for Paris and its population to topple the government of France (by and large, what is known as French Revolutions were revolutions of the Paris region, with the rest of France usually indifferent or actively opposed) while the former is the last large scale uprising against the Government (but it is unclear it would have taken place absent the humiliating defeat in the Franco-Prussian war). So they were no trend of uprisings to be ended almost a century later.

Note in particular that there were absolutely no violent uprisings of any significant scale in metropolitan France during the 70 years of the Third Republic (though this might in great part have been due to social changes having been triggered by the World Wars: many revolutionary new political and social changes were enacted during the World Wars or in their immediate aftermaths).

Besides, Mai 68 is much more aptly described as one the largest and most remarkable convulsions that accompanied the profound social changes which took place in between 1950 and 1980 in most advanced democracies than as a violent uprising against the then current Government. In other words, it is much better understood as a symptom of the baby-boom, the explosion of enrollment in higher education and the general change of attitudes towards sexuality and authority than as a political riot per se.

Why has there been no revolutionary reactions to national or international crises in the last 50 years. I am aware that there have been major riots since then, but why no revolutions over the GFC, European Union etc?

Probably because independent, prosperous, aging democracies very rarely descend into revolutions. If you want a more specific answer, the relative decline of the political, military and plain demographical power of Paris (and its region) compared to the rest of France certainly played a role, as well as the aging of the French population in the last 5 decades.

What was the legacy of Mai 68?

This is the question implicit in the title, though it is absent in the body of the text. Well, as Lennart Regebro's answer correctly notes, the political legacy was rather unimpressive in the short term. Interestingly, the two most powerful political parties of the time, the Gaullists and Communists, knew severe drawbacks in the the ensuing decade (the latter ultimately disappearing completely as a significant political force, and the former moving from its incredibly dominant position to second place within the French political right). At the level of social change, Mai 68 was part of a movement that changed deeply French social norms. This movement included the lowering of the voting age, the legalization of abortion and contraceptives and generally a much freer vision of sexuality, the generalization of higher education and of employment for both men and women etc. It is unclear to what extent the events themselves played a role, but certainly many concessions were made with a definite fear of students rebellions degenerating in general strike again. From a purely positional point of view, the cohort born in 1948-1952 (so the typical high school graduate or young student in 1968) did very well indeed in economic and political terms through the span of their life (see for instance Le Destin des Générations) and arguably still represent the dominant social force in contemporary France.