Recent discovery by scientists from NASA's Goddard Institute for Space Studies  in New York suggests that Venus may have been habitable. 
Scientists used computer modeling of planet's ancient climate to estimate that Venus may have had a shallow liquid-water ocean and habitable surface temperatures for up to 2 billion years within it's early history.
It has been long speculated by scientists that Venus shaped out of ingredients similar to Earth's but evolved differently. 

http://i1243.photobucket.com/albums/gg541/Peter_April/dfgdfg_zps5h6xqkpr.jpg
[Picture of Venus and Earth]

Reference:
"NASA Climate Modeling Suggests Venus May Have Been Habitable"
https://astrobiology.nasa.gov/news/nasa-climate-modeling-suggests-venus-may-have-been-habitable/