Happy birthday, Rick Riordan! To celebrate, we’re having fans upvote their favorite mythological books written by the Percy Jackson author.

June 5 marks Riordan’s birthday, and gives us the perfect excuse to once again talk about all of his fantastic books. He has, of course, written more than just his popular middle grade novels, but he is perhaps best known for his ability to modernize mythology and create stories that entertain even the most ADHD demigods.

We’ve listed all of Riordan’s full length Greek/Roman, Egyptian, and Norse mythology titles published prior to today’s date. Now it’s your job, as fans, to battle on behalf of your favorite book. Has The Lightning Thief stolen your heart for all of time, or do you prefer Apollo’s terrible haiku in The Hidden Oracle? Perhaps you’d rather venture outside the Percy Jackson universe and declare your love for Team Kane with one of the Kane Chronicles novels. But don’t forget about our newest headlining hero, Magnus Chase, star of The Sword of Summer.

Here are the books within their respective series:

Percy Jackson and the Olympians

The Heroes of Olympus

The Trials of Apollo

The Kane Chronicles

Magnus Chase and the Gods of Asgard

We want a nice clean fight. May the best book win!

Which book is your favorite?