Electric Future ( with Butanol and Biodiesel for antiques)
Electricity is clean, efficient, cheap, and comes from many diverse sources. Electrical production and distribution systems are in place, and are more efficient than the production and distribution of any other fuel. Current LiIon batteries give good power and range. More advanced batteries (Li Sulfur, Li Air, Al Air) are in development, and could give greater driving range than any petroleum fuels. Aluminum-air and zinc-air fuel cell batteries can be refueled quickly with fresh metal fuel. Construction of powered guideways that provide electricity "on the go" will eliminate the "short range long trip slow recharge" problem.
But what about the older vehicles that don't run on electrons?
Butanol is nearly perfect for old gas guzzlers, it can be made from any biomass feedstock used to make ethanol, but unlike ethanol does not require special engine modifications. Butanol has more energy per gallon than ethanol, and unlike ethanol has little adverse effect on milage.
Biodiesel is for diesels (natch), and can be made from various oils and fats. Certain algae are very prolific oil producers, and in the future may be the main source for biodiesel.
As for the other "also rans":
Natural gas is the only "fossil fuel" with a renewable source, clean burning, but requires high pressure tanks for automotive use. Best reserved for stationary heating applications.
Ethanol is clean burning, but is inferior to Butanol as a fuel.
Hydrogen is clean, but expensive, inefficient, and extremely bulky. Driving range is a bigger problem for H2 than it is for electrics! Best reserved for those rare special applications where its high energy/low weight overrides its many serious drawbacks, such as fueling very big rockets and perhaps some large planes.
"Coal-to-liquid", oil shales, and tar sands all rely on limited fossil fuels, are expensive, will have to compete with biofuels, and are far too expensive (and polluting) to compete with electricity.