BSD, MIT or Apachev2 is my preference. I really don't like the GPL and it does tend to turn off some folks from using open source projects. I would not be too concerned about someone taking the work closed source even if you do go BSD.
Ok everybody want BSD, so it's the way to go. About someone closing the source in a proprietary application, who cares as long as we can still access and hack on our source BSD-licensed? Ok we have a license :) Thanks