For those that care to, go read KBB's selection criteria and you'll find that it is an opinion piece. They included vehicles like the Silverado Hybrid because not everybody can live with a Prius or a Mini. The Silverado Hybrid is the first hybrid option for people that require a pick-up for day-to-day operation, i.e. contractors, skilled trades workers, etc. Prior to this vehicle, they had no fuel efficient options. That makes it significant enough in KBB's eyes to include it in their list.
For all you diesel proponents, I'll play the devils advocate for a moment. Modern diesels, the newest, lastest, greatest, and *greenest* diesels with their particulate filters and urea injection, are still only required to meet Tier 2 Bin 5 emission regulations. What does this mean? Well, diesels have finally caught up to where gasoline powered vehicles were 5+ years ago! Sure, the higher fuel economy afforded by a diesel may give a reduction in greenhouses gases, but they still spew far more carbon monoxide, oxides of nitrogen, and other various hydricarbons when compared to most gasoline engines.
There is more to *green* than fuel economy numbers and carbon dioxide emissions.