Giphy Chrome Extension - Respond to emails, tweets & more w/ GIFs in a jiffy
4Gifs.com - Funny Animated GIF archive.
PopKey for Desktop - Quickly share ridiculous GIFs from Mac or Windows
Giphy - Search all the gifs and make your own animated gif
Vlipsy - Easily add your favorite video clips to any conversation.
Gifyu - Upload GIF Images and Share Pictures Online