wow that's a difficult one, I've looked at a lot of images, especially when I was studying photography. my favourite style of imagery is photojournalism, not usually technically perfect but rather a moment in time, too many to choose from. check out this slide show of some of the worlds most thought provoking and powerful images. WARNING CONTAINS MATERIAL WITH GRAPHIC CONTENT WHICH SOME MAY FIND DISTURBING http://www.worldpressphoto.org/50years/flash.html