Fractal Design always. I've also built a Define R4, Nano S, and Node 202 for the work, and the Define Mini feels like the sweet spot for me. Easy to work on, form factor offers a wide range of components, front door for a BD player and fan control (included), but still plenty of the Define series' dust and sound proofing. It sits in the office with its brethren, a silent black box with a discreet blue LED on top. I always mount the towers on Hama X stands with castors, because they are very heavy.