I use both github (I recently finished a PhD and so had access to the education discount) and free bitbucket (a budding collaboration hosts their private code there). I am the sole user for most of my repos (mostly software for data analysis and LaTeX drafts for papers), so bitbucket's five user limit for free accounts has not affected my workflow in any way. I do use github for code I want to release to the public (e.g., code associated with publications, side-projects that I want to share), as it seems like there is more of an ecosystem there and the website seems more conducive to easily finding other peoples projects.