The Lorax by Dr. Seuss

I would definitely consider Theodore Giesel, aka Dr. Seuss, as one of my favorite artists. One has to admire his one-of-a-kind illustration style, his sense of imagination and optimism, and his inspiring knack for poetry. His books, although obviously geared toward children, always communicate an important social message beneath their whimsical exterior. The Starbellied Sneetches, about racial equality, The Grinch, about overcoming materialism, Horton Hears a Who, about the dangers of mob mentality and minority oppression ("A person's a person, no matter how small!"), and the ever-popular Oh, The Places You'll Go. My personal favorite is the eco-tale, The Lorax, which brings a very unique emotional quality to its storytelling. The final words leave us with a challenge to improve the world we live in:

And all that the Lorax left here in this mess
was a small pile of rocks, with the one word, "UNLESS."
"But now," says the Once-ler,
"Now that you're here,
the word of the Lorax seems perfectly clear.
UNLESS someone like you cares a whole awful lot,
Nothing is going to get better. It's not."