Image Sharing Sites are the sites which allow the user to publish or upload their photos online. You can comapre image sharing sites on: http://silvery.com/PhotoSharingComparison.html and can select the best site to share your images.
Image sharing is an effective way to raise your website's traffic. your images that you are sharing works as a banner or ad ; put a logo of your website or a link to your website or your brand name over the image you are sharing then of course some people will get attracted towards it and will visit your page or website as images are more attractive than text few image sharing sites : Instagram Flicker DeviantART pinterest photobucket tinypic and many more....
I'm agree with @rahush 's list. In these, Pinterest is good. But Why are you guys forget to suggest Facebook. It is also one of the best site for image sharing. And still Facebook's daily image sharing ratio is greater than Pinterest. So Facebook is the best. One more thing. Try to share Fresh, Interesting and Informative images with your site link. So it is automatically shared by other people and your SEO will become strong with number of backlinks.