Nanocade. Besides, designer Rasmus Sorensen's actually selling the miniature arcade cabinet parts for just $229 right now, which makes the decision to finally build your own MAME machine a wee bit more affordable. You'll still need to supply all the internals yourself, including buttons, an arcade stick, a monitor and glue, and even should you succeed, good luck prying guests away from your new coffee table conversation piece. Find the basic kit in your choice of Midnight Black or Arctic White at our source link.
Note: It's a bit of a bummer, but the Nanocade website says that handsome curved control panel displayed above actually isn't part of the initial kit -- it comes with a pair of flat pieces that meet at a (seemingly) wrist-chafing angle instead.