There are some pieces that even when they are complete, still look like works in progress. I LOVE IT. After all, that could probably apply to the majority of doodles.
Adara Sanchez Anguiana is a Spanish artist who has perfected the art of imperfection. If her illustrations looked any more "complete", I don't think they would have captured my attention as deeply. Her favorite subject is the human form and WOW is she good at making every pose and angle of it mesmerizing. My favorite is her Take Off Your Clothes series, there's something great about how she captures people just in the middle of a quick intimate motion.
Spend enough time on Tumblr and you're bound to find a mountain of treasure ("El Dorado" be darned!). One such treasure is Robert Alejandro (aka The Sketching Backpacker) whose book is filled to the brim with locales from his constant travels. Even more interesting though, are his Leave Sketches, in which he takes ordinary, unnoticed-leaves and makes them the spotlight of the drawn page.