I'm about to start Descent 3, from GoG.
Addendum: I was up til 2:00 a.m. trying to get the controls configured to work with my Sidewinder Force Feedback 2 and messing with different rendering devices, graphics settings, and command-line switches, so I haven't really played yet. It seems like D3D doesn't work (screwed-up menu text, cursor artifacts), and using the included Glide wrapper is less hassle than using Open GL (it messes up my desktop size and re-orders my icons). I finally got the joystick configured to let me at least finish the tutorial - I had to un-bind the joystick throttle to keep from moving forward all the time.
I found a lot more resources online for Descent 1 and 2, I guess because the source code is now open source or something. Any hints, tips, tricks, etc. are appreciated! I hope to start playing the actual game in a few hours.