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 dog wearing a red hoodie (I think it's a Pug, not sure) while the text "SRSLY GUISE, SRSLY" appears. This is a great one to use whenever you feel as if everyone is getting head of themselves / jumping the gun.