My all time favorite SW games are X-Wing, Dark Forces, Rebel Assault II, Shadows of the Empire, the Rogue Squadron games, and finally Star Wars: Dark Forces III: Jedi Knight II: Jedi Outcast along with Star Wars: Dark Forces IV: Jedi Knight III: Jedi Outcast II: Jedi Academy.
Tie Fighter was fantastic too, but I never clocked in the insane number of hours I did with X-Wing.
If I had to pick one favorite, it would be a very difficult toss up between Dark Forces and Shadows of the Empire. I wish there were more Star Wars games that didn't involve lightsabres and the force.