The Atomlab Trailpimp stem is simple but effective - it's basically just a lump of aluminium with a 22.2mm bar clamp (using four 5mm bolts) and an expanding-wedge steerer tube clamp.
The stem is available in a super twitchy 40mm length as well as a more conventional 50mm length. A 5mm allen bolt expands twin wedges that compress onto the steerer tube, creating good contact, although don't over-tighten it because you can easily damage the steerer tube.
This set-up does, however, keep the clamp bolts out of harm's way - you won't bash your knees on this sucker. It also has a bombproof, stern looking construction and should be able to cope with all you throw at it.