LEGO is such a versatile toy so what better way to showcase that then make a Game Boy Advance SP out of it? Retro Stash Repairs made the LEGO/GBA hybrid entirely out of LEGO bricks, including the hinges, and a IPS LCD screen for the sake of size. The attention to detail is truly impressive.
Game Boy mod related: a custom Game Boy Color made of brass and the Game Boy Pocket SP.