GBA Micro is a contender for it's great build quality ... if only the screen were not so tiny.
The folding GBA SP with the nicer screen from 2005 is really nice as well, but it lacks a headphone port, which is awkward.
My pick also lacks a headphone port, but I have worked around it. I choose the iPhone Xs, big bright screen in a small package, and I never run out of things to read.
Today, 6:36 AM