I didn't get a lot out of GEB, but I pored over Metamagical Themas [0]. It was perfect for a teenager just learning programming. The bite-sized nature of it makes it extremely approachable - perhaps a case of constraints (periodic column of N words) leading to more creative output.

[0] https://www.amazon.com/Metamagical-Themas-Questing-Essence-P...

The Ancient Paths by Graham Robb [1]

Trigger Warning by Neil Gaiman [2]

Metamagical Themas by Douglas Hofstadter [3]

[1]: http://www.amazon.com/The-Ancient-Paths-Discovering-Celtic/d...

[2]: http://www.amazon.com/Trigger-Warning-Short-Fictions-Disturb...

[3]: http://www.amazon.com/Metamagical-Themas-Questing-Essence-Pa...