This thread on the subreddit Background Art (which is overflowing with amazing art if you like this kind of thing) has a particularly beautiful collection of images from the 2006 anime adaptation of Taiyō Matsumoto's manga Tekkonkinkreet.
The story revolves around two orphans living in the once-wonderful but now slum-like city of Takaramachi. Kuro is the older one and a street-smart punk who believes that Takaramachi is his town, while Shiro is younger and is often stuck in his own head. The story details their lives trying to survive in the city, but this art does a great job of capturing the film's tone. Enjoy some of the pictures below but check out the reddit thread for the full gallery.