After ten years and heaven-knows-how-many Pyro ships destroyed, I still play the Descent series. More so now that they've been re-optimized to take advantage of newer hardware, OSs and graphics capabilities. And the funny thing is, D3 will STILL tax your hardware.
The only downside, of course, is the interstitials. The plot is relatively banal and predictable, and the human characters are pretty badly designed and rendered. I usually just hit the Space Bar or ESC to skip 'em -- except for the end sequence, of course, because I'd earned that one. ;)