The approach I find interesting is an all electric car with a gas engine dedicated solely to charging a battery system and providing electrical power, rather than directly driving the power train. My liking this approach has nothing to do with "green" or any other politically correct viewpoint, but simply from an engineering point of view, I see so many advantages to this design approach. For example, imagine separate drive motors directly on each wheel allowing ideal traction, direct and efficient drive, breaking and energy recovery. Such a car would be efficient and a great performer as well.
Many technologies are now available to make this practical. We have very good batteries for storage, high power fast switching semiconductors for efficient power conversion, control theory advancements that allow good system understanding and high speed processors for advanced, accurate and fast motor/generator control.
Batteries just do not have the energy storage density of gas/oil and other chemically based fuels and really, they can't from theoretical limits (lithium is the lightest element for making batteries and there is only so much improvement possible from where we are now), and people don't like the idea of limited range. However, give them the range with the gas engine charging system, and they will do their best to charge from local wall sockets at home and at work when they are making short range trips. This is an approach without unacceptable compromises, and can work for everyone.