I love the New York subway system, I use it every day and it does make my life so much easier but thats about it.
Most of the stations in New York looks ugly at best (14th st. A,C,E station is cute but thats the only one).
Today i found this picture of a U-Bahn (subway) station in Munich, Germany (can you Believe its a subway station ?). So amazing and inspiring that I' m actually considering moving there just so i can visit it everyday.
I also found this beautiful station in Amsterdam (although from my expirience the subway does not really work well in Amsterdam and anyways bikes are so much more fun :)
Now if you really want to see amazing subway stations (Interior only) you should visit Moscow, I was really amazed to find how beautiful their stations are (I have been there) each with its own theme and since they didn' t have any signs in English I Used to call them by their theme ("The Olympic station", "The Glass station" and so on).