What more can be said about "The Dark Knight Returns?" It's a dang fine Batman book that changed the interpretation of Batman as a character and shifted the course of the entire comic book industry. Aside from the tone and tight storytelling, a big part of what makes TDKR great is Frank Miller's pencils with Klaus Janson's finishes. The artwork is still some of my favorite art in all of comics.
Here's my homage to arguably the best Batman book ever written: