IMHO a list of well-maintained PPAs is a useful commodity for a Ubuntu user to have. Perhaps some of you have links of this kind to share? Or maybe you've seen a review or list of PPAs (a blog post maybe) by someone, or some kind of PPA directory, etc.?
I am especially interested in fresh and useful packages targeting 10.04, 10.10 and 11.04.
Best Answer
Have you checked out Ubuntu Tweak? Not exactly what you are asking for, but I find the PPAs you can install via Ubuntu Tweak to be of high quality.
http://ubuntu-tweak.com/source/category/