This answer is great for seeing a visual diff between two files that are checked into git: How do I view 'git diff' output with a visual diff program?
However, I'd like to see a visual diff between two branches. So far, my best bet seems to be:
git diff --name-status master dev
which isn't very informative and not very visual.
Is there anything better out there?
git diff branch1..branch2
This will compare the tips of each branch.
If you really want some GUI software, you can try something like SourceTree which supports Mac OS X and Windows.