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 an animated gif of a guy drinking a can of Pepsi that has Science written on the side of it. The look of overblown satisfaction on his face makes it hilarious to use as a reaction gif whenever you defeat somebody in an online argument.