I used to have a Github account and later eventually deleted it. I felt Mercurial was a superior source control system and so I wanted to stick with that. At work we switched to using git. And that’s when I discovered gitextensions.
Gitextensions in my opinion makes git usable for me on Windows. My only real complaint with git was that there wasn’t a good gui for it on Windows. Git also has a few features that I can definitely say are superior to Mercurial, fast-forwarding for instance.
I’ve moved most of my open source code over to Github as of now. There are some things that I haven’t moved and probably will never move but will remain on Codeplex.