What are the greatest collaborations in history?

This interesting question arose in a Twitter conversation. Mike Brown at Brainzooming had referred to a great little post he’d written about the collaboration between John Lennon and Paul McCartney of The Beatles. In an exchange following Mike’s tweet, we started discussing great collaborations.

Of course, the term “great” depends on the metric. Millions have received pleasure from the Lennon/McCartney collaboration, but that partnership was perhaps rather trivial in world-historical terms. Thus my question, and it is for you, the reader. What do you consider the great collaborations in different disciplines — politics, science, music, and the arts?

For example, consider Thomas Jefferson and James Madison, who not only closely collaborated in their political philosophies, but also effectively controlled the US Presidency for 25 years (if you count the third and less significant of their group, James Monroe). Louis Brandeis and Felix Frankfurter also come to mind, since their multi-year collaboration had enormous impact on progressive law and US politics during the middle years of the 20th century (described in this book).

These examples stem from my background in political and legal thought. I’m interested, however, in the great, dominating partnerships in any discipline — particularly those with which I lack familiarity.

Please comment and provide your best examples. I am seeking thoughts from readers because you have so many different backgrounds, interests, and values. Take a moment to give it some thought and provide me with some feedback about your candidates for the truly “great” partnerships.