Biodiesel can be produced from algae grown in salt water, so there is no need to ruin rain forests to grow palm oil trees or use other land that is needed for food production. Diesel engines use 30% less fuel than petrol engines too.
With hybrids the disadvantage is the cost of buying and replacing batteries and the impact of that.
To find economical cars see:
http://www.greenvehicleguide.gov.au/GVGPublicUI/ApplicationFirstStartTaskWebForm.as px
Use the Advanced Search and sort by Fuel Consumption.