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
All the GIFs - Search all the GIFs right from your Mac
Gifyu - Upload GIF Images and Share Pictures Online