This was very sad news to hear. I've come to appreciate his movies more over the last couple of years and his particular generation of actors. Seeing a documentary on The French Connection a few years ago made me realise how ground breaking the film was for its time. Shot in a raw, documentary style which was unheard of back then.
I recall hearing that William Friedkin (who was known for his somewhat provocative directorial style) had deliberately kept Hackman on his toes while filming The French Connection, even to the point of keeping him on edge to encourage the character of Popeye's natural aggression which came off so believably on camera. One thing is for certain, the film would not have been the success it was without Hackman's commanding presence on screen.
What was great about Hackman was that he was not the traditional pin-up actor that Hollywood has always celebrated. He just had sheer force of charisma and acting prowess. When he was on camera, whether in moments of quiet reflection, authority or rage, he held the audiences absolute attention. What a talent. RIP Gene and his wife.