I infinitely prefer BitBucket to GitHub. I guess GitHub is great if you are working on public or open source projects, but BitBucket seems to be much better at handling internal (private) projects to me.

Their lack of popularity also seems to translate to a lower attack profile, so I feel that my private projects are safer on BB than GH.

I've evaluated many issue trackers too, and none of them seem to come close to Jira. Yes it is slow, but the depth of features (and plugins) are great, and BitBucket works seamlessly with it.