Tamora Pierce is pretty good, but the books are not as funny. Heard good things about Artemis Fowl, but never read them. Might be worth checking Goodreads.com , which could help you find similar books. If you liked the fantasy elements, you could try something like Lord of the Rings or the Inheritance Cycle. Replied to this post cause I saw Rick Riordan, and I absolutely loved those books when i was younger!
Started Pegasus by Kate'O'Hearn now
On Riordan's website there's a subsection called 'Rick Riordan Presents' which aims to find people similar books they might enjoy if they have previously enjoyed reading the Percy Jackson books
There's also sequels to the Percy Jackson series including Heroes of Olympus and Trials of Apollo (fourth book for Trials of Apollo is released sometime in October/November). By the way if you haven't read them already they're super fun reads .
The Kane Chronicles and the Magnus Chase series (both trilogies) are also related to the main demigod world as well (both worth a read).