Everything from Alienology to Wizardology. They have a good feel to them, and I like that they're interactive and full of information.
Dungeons & Dragons materials
From Starter Sets ($19.99) to sets of dice ($5.00), from the Player's Handbook ($49.95) to DM screens ($14.95).
Minecraft: The Complete Handbook Collection (Scholastic, $35.96)
These are good both for learning about the game and as a reference for when you don't have everything in your head.
Amulet series by Kazu Kibuishi, starting with Stonekeeper (Scholastic, $12.99)
These graphic novels have great illustrations!
Zivia Avelin, December 2016