Well depends how deep you want it to go.
I felt my mission Nocturnal had a decent story, better than most.
Actually now I think its time to revive her, the MEC is all done, and I never properly finished it.
But I don't really remember any signifagant missions, but my team AGP-
www.agp-ofp.tk/ is making a new campaign with a good plot by Tomasz. I think its gonna be a pretty cohesive campaign when its done.