I have 2 1tb drives and a 500 and 750....I have 2 different OS and assorted software programs. I use 1 tb for back up, movies, music, family pictures and family movies. I use the other 1tb for backup of the other 1tb.
I have told my wife, kids grow up once so take the pictures now. Think about, nowadays its easy to fill a sd card of pictures and movies and then go through and erase some of them later as opposed to takes several rolls of 35mm film and have it developed as the way it was.