Pegasus: The Flame Of Olympus just pulled me in from beginning to end. There is so much action! The Flame of Olympus is also very much like the Percy Jackson series because of the reference to mythology.
Emily (the main character) was inside her house during a very large thunder storm and heard a crash on top of her roof. She and her father live on the top floor of an apartment building. When Emily went up to the roof she saw a giant winged horse. Then she realized that the horse was Pegasus the Olympian. . . . Their adventure has MANY adventures attached to it and many more characters are involved but it all started out with Pegasus and Emily.
I highly recommend this book!