I use Farcebook, Google+, Zenfolio, Flickr Pro, and 500px.
500px is unique in the presentation. I like it; don't yet love it, but it is growing on me (new user to it). Zenfolio has been great for a while. I use Flickr for some quick uploads. Farcebook as I take photos of my daughters travel basketball and post for the kids and parents. G+, because I like the communities.