I loved "Prof. E. McSquared's Calculus Primer" when I was learning Calculus (look for used prices):

http://www.amazon.com/gp/product/0913232475/ref=olp_product_...

Home page here: http://www.math.sjsu.edu/~swann/mcsqrd.html

Fun and funny, written in a comic book format. It illustrates the concepts in such an entertaining style, but makes the point better than many textbooks.