I recently pried myself from FreeSpace 2 and gave 1 a shot and I'm glad I did. An amazing game which still stands on it own merits despite the sequel, a great story line and some pretty awesome missions.
The addon missions are a bit meh but playing through the excellent main campaign is pretty much mandatory if you want to get more enjoyment out of FS2 and it's well worth your time and money.
5/5!