10. Volkswagen Jetta TDI

The diesel-powered car is one of those great ideas that Americans just haven't latched onto yet -- but the VW Jetta TDI is certainly doing its part to help. Its all-new 2-liter turbodiesel engine produces near-hybrid fuel economy with stronger acceleration and less electro-mechanical complexity, plus it runs on low-sulfur "clean" diesel fuel and meets 50-state emissions standards without the need for any sort of AdBlue-type fluid. VW has wrapped this engine it in the Jetta, one of my favorite family sedans. Thanks to a $1,300 federal tax credit, the Jetta TDI actually costs less than a comparably-equipped gasoline-powered Jetta -- and it gets double the fuel economy.