Once again, I have to fully agree with Pål on this one. Any respectable book on photography discusses the rule of thirds as a starting point photographers should use. That's not to say you can't and should not break the rules. The rules are a starting point and that's all. But, like I said earlier, you need to know the rules before you break them with any intelligience. The best pictures are the ones that break the rules because they add tension to the image. But, don't kid yourself, those photographers who create these magnificent rule-breaking images on a regular basis are quite aware that they are breaking the rules. They know when to break the rules and they will tell you why they broke the rules and why the image is successful despite breaking the rules.... BTW even if you think you don't use the rule of thirds, chances are you do. In most portraits, for example, you'll see that the eyes of the model are along the top (traditional) or bottom third (fashion or contemporary approach) of the picture.
Pål's comments on mature and immature images is certainly valid. When, for example, photographers start to take pictures of wildlife they want to "fill the frame" with their image. If they come to the realization that these closeups have been done a million times in zoos etc, they begin to back off and try to get the animal in its environment. Today's successful wildlife photographers are using a 20mm lens to get up close and personal with an animal in its environment. These are immature images which make people say wow.... "Filling the frame" is a good rule to follow. But it's the one that should and is broken most often by photographers who know better and know when to break it... In reference to some of the great shots that have been taken in the past that don't appear to follow any rules: Pål is correct again. These pictures are memorable because in their day they were seen as new approaches "immature" images. The shot of the soldier being killed would be mildly interesting today. Chances are critics would say the picture is soft and dismiss it. That's not to say It was not great in it's day for it's ability to capture the precise moment of a soldier being shot. With today's autofocus cameras and highspeed film this shot becomes a whole lot easier to get (in focus, in living colour and at 5fps the photographer would have a whole series on the guy getting shot. In my job at a daily newspaper I see hundreds of outstanding shots on the photo wires that would not have been possible just a few years ago. A lot of these never even get used. These are shots that would have made the history books 30 years ago... The times they are a changin.. Vic