My grandfather owned Wing Commander I, and when he broke his PC (a frequent occurrence), he left it with my father to be fixed. After a few days, my dad had fixed up the machine, and installed Wing Commander to test if the joystick worked.
I played that game every chance I got until my grandfather picked it up. I was five or six at the time, and I'm not sure that I ever got past the first mission, but I was absolutely thrilled by the entire experience. My friend came over and we would swap off playing the first mission over and over again, imagining ourselves as pilots on the Tiger's Claw, fighting for humanity. I even hid away Claw Marks, and I still have it to this day, a little worn, but the same copy from all those years ago.
Interestingly, I would occasionally see Wing Commanders in stores, WC2, 3, 4, so on... but I never got back into it until a friend in the fifth grade told me how Wing Commander III and IV had full motion video. This blew my ten year old mind to the point that I had to have it. Kilrathi Saga was released that year, and I wound up getting both it and WCIV for Christmas. Ever since then... I've been a dedicated fan for as long as I can remember. To me, playing that game wasn't just the first Wing Commander game to me, it was the first time I saw a computer game as something *more* than just a mindless diversion.