As far as US goes, there's an article in the NYT today that quotes the website greenercars.org which released a list of the "greenest" and "least green" cars.
The smart fortwo ranked first in non hybrid or non CNG cars available, and scored third overall. Scoring was based on mpg, CO2, recyclability, et al. Nevertheless, the lower scoring Toyota Yaris got the photo op in the story. They mislabeled the fortwo as an automatic transmission.