for the mass buying public, the diesel engine is the current eco route high miles for low cost and low tax brackets, hybrid is great but out of the price range of most hence why its so limited at the mo. the more its used the cheaper it will get.
advantages of electric, very few mechanical parts; power is direct so acceleration is very rapid. only 1 gear.
a mix of electric and hydrogen wold give the best performance for us people. as well as some of these concept gas turbines like jag used in their concept.