Venus - one day is longer than its entire year. It takes Venus 243 Earth days to completely rotate on its axis, but just 225 days to orbit the sun. Venus is one of two planets that rotates in reverse, called retrograde motion.
Retrograde: ~Mars appears to reverse its course in the night sky. This image by Tunc Tezel shows the retrograde motion by layering images in time series. The dotted line to right is Uranus doing the same thing.