Sol: A History would fit very well in here. Just beat it, it's technically solid, has great mission design (a bit on the hard side), and a very interesting plotline. I personally liked it more than INFA, which was ok but maybe not good enough for the Guide.
"Sol: A History: An alternate prequel to the original Inferno, Blaise Russel's Sol: A History details the history of Sol during the isolation. Watch as new powers declare independence, the old GTA crumbles, powerful new weapons enter the fray, and the totalitarian Earth Alliance rises to power. Fly the enemy ships that tormented you in Inferno, visit every planet in the Solar System, and take part in the unification of Sol. A masterpiece by one of HLP's most successful FREDers, it's a lengthy and challenging adventure."
*Review idea falls out of the sky and hits InsaneBaron on the head*