I tried Git Tower for Windows when it first launched, it was pretty nice but didn't hit the mark for me to want to spend money on it. If they're going to make "hard" maneuvers like rebasing and cherry-picking easy to do in the UI though, it may be worth another look. GitHub hasn't given really any attempt to expose that sort of capability in their UIs, and as someone who doesn't Git enough to put the time into learning the command line... very interesting.