One thing you might consider is a safe deposit box at a bank. There are a few things you need to worry about when planning for the unthinkable. The best case scenario is your hard drive fries. This can be fixed by having multiple redundant hard drives. However, these are in one location so if the next scenario happens (fire, flood, hurricane etc.) you can still lose everything so you need off site storage. Some online services you mentioned are good choices and will do just fine. However, if you already have a safe deposit box (pretty damn secure in a bank vault) you can just get a terabyte hard drive and back up once a month and put it back in the safe. I would recommend a combo of all 3 but that could be over kill.