Gif Central boasts hundreds of funny animated gifs. Only the best of the best make it onto this site, with most of them having an accompanying source. No tumblr-esque one-second-long disappointments. No obscure titles or descriptions.
This is the original Mind Blown gif, where explosions and fireworks appear as some guy in glasses is making hand gestures around his head. This is often used as a reaction whenever somebody brings up a fact that shocks people.