The Extreme presentation Blog is known for presentation recommendations, along with a few other sites like Stephen Few's Perceptual Edge or Junk Charts. Some have also taken to create great charts, like Juice Analytics, maani.us, Adobe's flex charts or Engauge's Digitalizer.
Some time ago I mentioned a sites to find nice Excel charts. Now there is a new option, built on the of popular Chart Chooser diagram. Well, here it is, live, thanks to their hard work: http://www.chartchooser.com/. Juice Analytics are also providing customized versions of the chart chooser, which will link with your own company's databases to automatically create or update charts. See their post at www.juiceanalytics.com/writing.