Which book is your favorite?
y kent he liek his own cooment
i liek book sun of neptoon becus annabeth is not in it (y)
^Hey, you're also not allowed to give kudos to yourself either.
The Last Olympian <3
From the first series? - The Last Olympian, due to it being a good and worthy finale.
From the second series? - The House of Hades, due to it having a lot of character development and intensity, though I'll also include some of the Blood of Olympus chapters from the POVs of Nico and Reyna here as well, for the same reasons.