I love all of his Xanth books. They're innocent but fun.
A souless scoundrel with the power to "unhappen" history threatens the future of the land of Xanth! Many malevolent menaces have imperiled the magical land of Xanth in its long and storied history. But none has been as despicably dangerous as the Dastard - a craven miscreant who sold his soul to a detestable demon for the power to erase events. Now the entier future of Xanth is at the mercy of his every whim. Only a young dragon-girl named Becka has the power to stop his devious deeds.
