Simply put, Decent Freespace is one of the funnest Space Sim, Action games I've ever played.
I loved the X-Wing VS Tie-fighter series, which my friend had.
When I first played Freespace, it was in german, since I lived in Germany. I bought a joystick just for this game. My friends and I would get together and LAN for hours in Freespace. The game still impresses us to this date.
Freespace: A must Have!