The two pictures I choose is from my favorite photographer: Henri Cartier Bresson, the pioneer of street photography. He is also a master of portraits photography.
This is one of my favorite pictures of all time. The reason I like this one is like what I have said in Pacha Kucha presentation: the man in the picture and the background made several wonderful geometry shapes.
The photo is focusing on the man, with a clear portrait and relatively misty background. The picture is full of motions.