I recently did a clean install on my Mac and I had to move only some system files. Everything else came in via BitTorrent Sync — it's a tool that I absolutely love. It's secure and decentralized and simple well done.
Now it is on version 2.0 and man are there some good changes. First the iOS apps got some love (and it was needed), but most important there is selective sync, which is really cool. Instead of just telling the app not to sync a folder, it shows placeholder files in that folder so your search works.. Double clicking a file downloads just that file and keeps just that file in sync. Amazing stuff, but that's a Pro feature which is $39/yr — chump change.
Everyone should be using this over Dropbox, it's just too good.