Molokai is a Vim port of the monokai theme for TextMate originally created by Wimer Hazenberg.
Ranked in these QuestionsQuestion Ranking
Pro Looks great
Pro One of the most common dark themes
Default for Sublime Text, avaialble on IntelliJ products and Eclipse via plug-in. Usually ranked in top 3 of highest downloaded theme for a IDE.
Pro Easy to install with Vundle
Pro Strong enough contrast
Without being fully black on white (which is good on modern already very contrasted screens) it remains pretty dark compared to many alternatives; making it more readable.