Where Stats Come Alive!NationMaster.com is a massive central data source and a handy way to graphically compare nations. Using the nationmaster form, you can generate maps and graphs with ease on all kinds of statistics. What's more, you can select exactly which countries you want to include.
They currently have 646 stats, and this number is increasing all the time.
You can also view profiles of individual countries including their maps and flags, as well as a full encyclopedia.