My absolute favorite book when I was a child was Fred Crump Jr.'s Marigold and the Dragon. It is such a shame that it is out of print. It was originally written in 1964 but there was a later edition in the 80s that redid the illustrations making the princess African-American (I think because Crump put in a lot of effort retelling/illustrating popular fairy and Bible stories for an African-American audience.), but even that is out of print.
I'm quite surprised it is out of print actually since there is such a call for books about intrepid princesses who do not lay down and roll over waiting to be rescued. The popularity of The Paperbag Princess comes to mind.
Here's my brief synopsis:
Marigold is a lonely princess and even though her father has told her never to climb the tower she says, "Fiddlesticks!" At the top of the tower she discovers a sad and lonely dragon. The dragon tells her that he is really a prince. Marigold goes on a quest to mix a potion for the dragon to turn him back into the prince but when it doesn't work, Snigglefritz (as the dragon is called) admits he lied. But instead of being disappointed, Marigold admits she is glad he is not a prince (they chase peacocks, so who wants 'em?) and they become the best of friends.
See what I mean? Doesn't that make you want to read it?
What was your favorite childhood book? Is it still in print? Lucky you.