One of the reports that I am getting a lot of head nods and "we need that" statements from out in the field is the "Project Storyboard" report from the free content pack "Customer Solution Pack"
This crystal report provides a one pager -- print it out or copy it into your PowerPoint deck (we're hoping to dive right into Clarity, but we can't change the world right away) -- where you get access to cost and hour information, whose responsible, the "what did you say you were going to do, did you do it, and what's next" section, as well as outstanding issues and action items. Use it the way it is or tweak it.
If you've used Clarity before, you can see where we're pulling all this information -- all inside the Project object. I wrote an article about how other companies have used this in an article in our Flipboard.
Let me know what Clarity reports have saved you some time!