My favorite book series is the Magic Tree House.  So far, I have read five of these book, and I'm reading number 6 now!  I read the one on dinosaurs, the one about knights and castles, plus one about Egypt, one about pirates, one on ninjas, and right now I'm reading about the Amazon.  The next one is called "Sunset of the Sabertooth".  

I like the series because they are fascinating.  Once I read the first book in the series, I fell in love with it. They are very, very, veeeeery cool.