Gran Compe ENE Ciclo Tire
No idea. Never seen anyone riding them, or read any reviews.

Challenge Parigi-Roubaix
They feel awesome, but they're a lightweight tire. If you're looking for flat protection, these aren't it.

Panaracer Pasela Tour Guard
I ride Pasela TG 32 folders and they're awesome. I take them on gravel paths all the time and the only thing that has flatted me out has been a blackberry thorn. They're smooth rolling, reasonably light (kevlar bead model) and decent durable tread with flat protection. I weigh 230 and have not had any sidewall problems.

Panaracer Ruffy-Tuffy
Heavier than the Pasela TG folder. Rolls smooth, feels a little stiff in the casing. Less comfortable than the Pasela, more comfortable than the Marathon. Overall good tire. I'd trust it on packed gravel.

Schwalbe Marathon
Good tire, but on the stiff and heavy side. There's almost nothing I wouldn't ride this tire on. Very flat resistant with a durable tread compound.

Vittoria Cross XN Pro
Challenge Grifo XS
Both are CX tires with microfile treads. Good for hardpack-to-concrete transition courses, unnecessary for road riding with a little bit of off-roading thrown in. A good road-touring tire like the Pasela TG or the Marathon offers enough bite to handle more off-roading than you'd think. In the fall, many of us with the Seattle Randonneurs will be riding the 3 Volcanoes 300k, which about 10% is gravel service roads; it's highly unlikely that you'll see a CX tire on anyone's bikes. 35 - 37mm touring tires; definitely. But not much in the way of CX tires.