game boy advance
Game Boy Advance has wonderful ergonomics but sadly the original screen was not lit in any way. I have done a few frontlit modifications similar to those I did with the Game Boy Color but the real showstopper with the original GBA is when you install a backlit screen for the AGS-101 Game Boy Advance SP, which can be done with a little internal cutting to make space and uses a custom adapter to connect the ribbon to the motherboard. It really does make a huge difference. In addition to this of course there's the usual coloured button and shell combinations to customise further!