I vaguely remember the day I got FS1(holding and looking over the Typhoon box with the fold-out flap, and finally deciding to get it, partly due to the 'Descent' name), and FS2(Oh, a sequel. ~grab~). Both were totally previously-uninformed purchases I happened upon at CompUSA(IIRC).
I had been a fan of the X-Wing/TIE Fighter games; the FS ETS system was a good bit more logical than the X-Wing energy systems(My X-Wing has to drop from 100 MGLT to 88, just to trickle-charge my lasers?), and afterburners made for much more dynamic combat(the TF Missile Boat did have the SLAM system, but that was the only thing remotely comparable). Those were the things I recall striking me first(obviously, the SW universe had more narrative to draw from).