HDD + time machine + 2x yearly DVD (one stored offsite at sisters). photos are all we have from years of life - friends don't let friends @#$#@ around with back ups.
I have experienced lovely moments, being in nature with friends, experiencing a stunning sunset, when the moment was ruined by some who were more occupied taking selfies with "we're so awsome!" faces. I prefer moment and memory over photo.
Then I inherited a couple of albums of photos from my mother when she died (long ago). A lot of pictures of flowers and landscapes none of which is in itself beautiful enough to be of any purpose for me. And a lot of pictures from her friends, most of which I actually do not know or have contact to.
Most of my paper based photos were accidentally ruined by mold in a wet cellar. I was very annoyed when I discovered it, but then I realized that the pictures sat there for years without being looked at anyway. I was forced to let go. And in the end it was okay.
That said, after all, I recommend to everyone what you said: Make f*#@in' backups fer chryslers sake!
I'm doing everything I can to make sure that they will be able to see what their life was like growing up.
I literally feel like an archivist at times. I go through a lot of trouble to document and preserve their life so they have something to look back on.
1) Photos and videos ... I have a local and cloud copy of them all [1].
2) Notes I send via email to addresses currently hosted on GMail but at an email address at my domain (looking for a better solution in terms of ownership on this)
[1] http://www.theguardian.com/technology/askjack/2012/feb/23/as...