I don't get it. You can improve the Excursions off road performance significantly. Bushwacker cutout fender flares, 38" tires, gears, lockers. Done. Florida trails are cake, so is much of the west I've seen. All the hardcore trails I've been on require little jeeps or 4 wheelers, motorcycles, or MarkI hiking boot. I haven't been anywhere where a Superduty won't fit, but mini SUV's will without damage. Our jeeps got wasted dragging on rocks and trees. Bikes are more fun. Which the Excursion can tow a dozen of. It's hard to pick a middle sized vehicle, when there aren't any middle sized trails.
A pretty XJ can't be great offroad. But I'd pick that as well, as long as it was the real deal with the scars to prove it. Just stinks that it has no frame. Get used to welding boxes into the unibody!
I'd also have to mention the YJ. My favorite jeep. Cheap, simple, reliable. Just add axles, SYE, drive shaft, suspension, CJ dash. Seats four, is fun.