After having to replace the radiator on my less then a year old '06 TJ (oops!)... I ordered Rusty's Radiator Skid. This skid is well built, and it not only protects the bottom of the radiator, but also something from coming up from below and hitting the front of the radiator. During the install, I was amazed at how exposed the radiator was!
The install was fairly easy. It took about twenty minutes once I figured out that I had to turn the steering wheel all the way to the left, then to the right, to get the skid to fit in place (the steering was in the way if the wheel is straight).
The picture below is with the wheels straight. The steering is super close to the skid, but the skid does clear everything and it fits perfectly.