Definitely, John Ringo's entire Posleen war series would be fantastic on the big screen.
If the ACS/Posleen stories get made then the theme song is definitely:
March of Cambreadth by Heather Alexander
Axes flash, broadsword swing,
shining armour's piercing ring
Horses run with polished shield,
fight those bastards till they yield
Midnight mare and blood red roan,
fight to keep this land your own
Sound the horn and call the cry,
how many of them can we make die?
Follow orders as you're told,
make their yellow blood run cold
Fight until you die or drop,
a force like ours is hard to stop
Close your mind to stress and pain,
fight till you're no longer sane
Let not one damn cur pass by,
how many of them can we make die?
Guard your women and children well,
send these bastards back to hell
We'll teach them the ways of war,
they won't come here any more
Use your shield and use your head,
fight till everyone is dead
Raise the flag up to the sky,
how many of them can we make die?
Dawn has broke,
the time has come,
move your feet to a marching drum
We'll win the war and pay the toll,
we'll fight as one in heart and soul
Midnight mare and blood red roan,
fight to keep this land your own
Sound the horn and call the cry,
how many of them can we make die?
How many of them can we make die?