Is there a good (visual) Git tool for Mac OS X or Windows? [closed]
Windows has TortoiseGit. It is not as mature as TortoiseSVN, but I've been using it and it works well enough for my purposes.
Screenshot:
EDIT [Dec 2014]: I'd also recommend looking at Dan's answer. Github's UI is probably the most mature/supported tool out there now (even if you don't use Github!)