In that form factor I really like the NFC Systems S4 Mini as far as small run "boutique" cases go.
I have one those as well. It's very high end as well. Fantastic work. Although, you can't fit a full GPU or a PSU in there. You have to use a DC/DC power supply and use a power brick. Going to make a full AMD build out of it once all there new stuff is released out into the wild... hopefully with a mini itx GPU of their new line of cards.