I'm using Bitbucket for private Repos. Really easy to use.. But I need to give GitLab a try soon, looks great.

I am a student and I use GitHub backpack. This gives you besides other neat things, free private repos.

I'm using gitlab mainly because of habits :) i'm using it at work and it is simple for me to use it at home :) I guess the most important thing for coders is to feel at ease with the tools you use :)

We use BB for weekend projects. Because BB allow private repo for free. And once you habitual with free stuff you also refer in your developer circle. And your developer friends already use BB. So I think this the only reason for using BB.

None of the listed.

I use Visual Studio Team Services and have a self-hosted Gitea-Server too.

Well it depends. If you only need a few private repos for hobby projects, I would go with bitbucket. Because of the unlimited private repos, for free.

If you're planning bigger, like small company wise, I would go with a selfhosted GitLab.

GitLab. Everything GitHub is (and often with more features) plus that marvelous CI tool. More people should be using it.

It's also open source, so there's that.