I want to recomment Git to my boss as a new source control system, since we're stuck in the 90s with VSS (ouch), but are the tools and 3rd party support good enough yet?

Specifically I'm talking about GUI front-ends similar to TortoiseSVN, decent visual diff/merge support, as well as stuff like email commit notifications and general support from 3rd parties like IDEs and build systems.

Even though this will be used by programmers, we really need this kind of stuff in our team. I don't want to leave everyone stuck with a new tool, and even a new source control paradigm (distributed), with nothing but a command-line app and some online tutorials. This would be a step backwards.

So what do you think... is Git ready? What decent tools exist for Git and what third party development apps support it?

EDIT: My original question was pretty vague so I'm updating it to specifically ask for a list of available tools and 3rd party support for Git. Maybe we can get a community wiki post with a list of stuff.

I also do not consider 'use subversion' to be an adequate answer. There are other reasons to use a distributed source control system other than offline editing - private and cheap branches being one of them.