SmartGit/Hg has a great interactive blame display. You can hover over commits to see the commit message, click on them to go back, etc. If you put the focus on the "View commit" select, then you can use the up and down arrows to go through the commits. You can also select different previous commits for the comparison window. Very easy to use and flexible.

IntelliJ IDEA also has a pretty nice blame panel. It's not as full-featured as SmartGit, but it's right there in the editor for any file with a quick Alt-G-N.

I would definitely recommend trying out SmartGit.