GMC Sierra 2500

 The all-new Sierra 2500 HD shares its chassis with the Chevy Silverado HD but wears Prada instead of work boots. It offers the same three cab styles, five wheelbases, two bed lengths, and three engines: 6.0- and 6.0-liter gas/CNG V-8s and our favorite, the Duramax 6.6-liter turbo-diesel with the Allison transmission. The 2500 HD boasts aggressive styling, über-luxurious interiors, and carlike sophistication. The upscale formula must be working: One in four buyers opts for the top-trim Denali.