The public library in Seattle is one of the most interesting buildings I have seen shape-wise and reflection-wise. It looks really cool when there are cabs and other colored cars driving down the street because everything is reflected all the way at the top of the building. It was designed by Dutch architect Rem Koolhaas.
Here is a description about it from the website: "His 11-floor, 362,987-square-foot library, a dazzling avant-garde symphony of glass and form, has many innovative features, including:
A "Books Spiral" that displays the entire non-fiction collection in a continuous run; A towering "living room" along Fifth Avenue that reaches 50 feet in height; A distinctive diamond-shaped exterior skin of glass and steel.
The new Central Library's unorthodox shape, unlike any other building in Seattle, is the result of its use of five platform areas to reflect different aspects of the library's program; its form indeed follows its function. It includes a 275-seat auditorium and parking for 143 vehicles." [Seattle Library History]
It's at the corner of 5th and Madison in Seattle, Washingon.