Electric is nice, but it brings around its own problems, due to battery capacities that are nowhere near the energy density of gasoline. One either pays for very top-tier battery technology like what a Tesla has, or one gets a vehicle with a limited range.
Until battery densities get to where they can completely replace an IC engine, the most economical vehicles are probably diesels. I find it interesting how a Chevy Cruze diesel gets better MPG than a Prius, and is cheaper to boot. However, MPG isn't a new concept... A CRX can get 48 MPG, and that is without hypermiling (pulse and glide, tailgating semis, and other clownish antics.)