Just picked up one of these Covercraft windshield shades. Very nice.
I had a Heatshield roll up shade:
While the Heatshield worked and fit fine, it was thin material and would sag in the middle. The Covercraft is a little more expensive, but I like how it folds up accordion style rather than rolls up. Plus it is much thicker material (the panels are sandwiched foam I believe) and doesn't sag. Much better quality.