Personal anecdote: It was my first day working at the new job downtown. I was headed back to Rogers Park and as we passed the home on the left someone on the second floor mooned the entire train. They had their behind so far out the window that a slight misstep would have led to a very embarrassing tragedy.
Also, is anything as ugly as the back of one of those massive billboard signs? But I suppose if you overlook the Metra tracks you can get used to anything.