Mondrian: Gray Tree, Apple Tree, Line and Color, Composition and Broadway Boogie-Woogie (which may look the most like that Monopoly board). Some love the energy in this one, inspired by a move to NYC in the late 1930s. But I don't like the yellow lines as well as the black ones.
MOndrian has written quite a bit about the theory behind these paintings. But the reading is difficult. Essentially, he is interested in a stable balance of forms, thus no diagonals (which add dynamism and energy). Each shape is different and there is such a subtle balance between the lines, white, and colors that curators can spot a fake immediately.
While these might be easy to copy now, remember he is one of the first to create such new works in the 1910-20s.
Just in case anyone wants to see any previous "classes" in this vein, the posts are:
class 3 http://www.freerepublic.com/focus/f-chat/1419876/posts
class 2 http://www.freerepublic.com/focus/f-chat/1414727/posts
class 1 http://www.freerepublic.com/focus/f-news/1410117/posts
RP