The headlights on my Grand Cherokee were pretty well fogged up. I already had bought the Meguiar's Headlight Restoration Kit a couple years ago so decided to use it. The results aren't perfect, but damn if it's not a pretty significant improvement.
Here's before & after shots of the front of the car:
And the driver's side headlight which needed the most work:
Hey look you can see my bald head in the reflection now!