I'm a loyal snapfish user from way back. It was the first photo sharing site I used, and I still do. I like that I can edit my photos right there, change coloring, add borders, etc and then pick up the photos at my local Walgreens. But...
I've been using shutterfly lately. Why, you may ask?? Because I received a very nice email from the man in charge and he said that Shutterfly will never require you to make a purchase to maintain your photos. Also, Shutterfly offers "share sites". This is like your very own website where you can not only share photos but you can send messages to people, and stay in touch. I have two. One for family stuff and one for my Rick pics.
I haven't done much with photo editing on Shutterfly, but I believe the option is there.
There are many other photo sharing sites. The only other one I have used is Kodak Gallery. They have a purchase requirement.
If you use a different photo sharing site, let me know. I'm interested to see how they work and what people find works best for them.