Another vintage coupling, and one of the most famous in all moviedom, having jointly-appeared in the likes of Cleopatra, The Taming of the Shrew and The VIPs (among others).
The pair, married (twice) between 1964 and 1976 (with a briefly-divorced period from '74 to '75), had their most memorable roles opposite each other in Mike Nichols' film version of the Edward Albee stageplay. Nichols is renowned for his uncompromising approach to relationships (check out the lesser-seen Carnal Knowledge), and this courageous effort is no different.
Onscreen Chemistry? The pair share a vitriolic relationship which is hardly romantic, but it showcases some of their finest work as they head to some dark places as a couple.