If you are really worried about losing or forgetting something, an OS restore is a great reason to upgrade your HDD! Keep everything on your old drive and do a clean install on the new drive.
Most everything you want to transfer is inside of your user folder... app data, favs, my docs, my pics, etc...
Either way you choose to do it, I find it is a 1-3 day process for me. But I have tons of apps! TONS!!!
Your saved passwords may come over using F.A.S.T.... not sure if there is any other way. But it is never a good idea to set your browser to remember those anyway!