I love the creativity exhibited when people get to design their own cases for small form factor computers, and the diversity you see in personal tastes is great! Reminds me of the early-mid 1980s when people would have DIY wood, acrylic and metal enclosures of all shapes and sizes.
For me it would have to be a cluster of Parallella boards mounted vertically in a 19" subrack frame, in a desktop enclosure, with perhaps a front panel made from smoked acrylic. Yes, incredibly '80s! A nod to the I started building as a kid but never got to complete
Cheers,
Andrew