I reach for my Spacetec SpaceOrb 360 whenever playing Descent. It's an old 6DoF controller from the Win9x days, and it came bundled with a Descent II demo for good reason.
However, it requires an old-school DB-9 serial port, and the USB version never materialized. Furthermore, since Spacetec went under, the controller's fanbase had to make their own 2000/XP drivers. Too bad there are no Vista drivers at the moment.
IIRC, 3Dconnexion's devices use the same underlying technology that Spacetec did. For some reason, though, they've opted for more of a puck shape as opposed to the spheres that Spacetec used.
The only issue with getting a 3Dconnexion product is that I recall reading that they do not present themselves as DirectInput devices with their typical drivers, as they are intended for use in CAD products and the like as opposed to games.