For family sharing, I try to keep it very simple. I use Shutterfly but Flickr is a good alternative. I typically post a relatively small number of photos - only the best and leaving a desire for more. 24-40 images is plenty from the longest trip or gathering. I assume no prints will be ordered.
Occasionally I post images on my website (through Zenfolio). I treat them like any other event I shoot professionally. The quality of print available is a little better, and the images I share are less personal. And family can order their own prints at cost. I allow downloads of images for Facebook, etc. I do this for larger family events.
I just got back from a 9 day trip with family. I photographed some tourist sites, a parade, and some artistic images. I'll end up sharing 30-40 images or less out of 1500 images captured.