FreeSpace and its sequel FreeSpace 2 are the definitive space combat sims - great gameplay, great graphics and an absorbing storyline. I've never seen them earn a review score under 90%.
However, FreeSpace 2 was released way back in 1999, and FreeSpace 3 doesn't seem to be forthcoming...
Do you want a FreeSpace 3? If so, sign this petition!
If you've never played FreeSpace, give it a go. The games are old, but you wouldn't guess it.