Sync Services Comparison
Ellis Hamburger’s comparison of various online sync/storage services at The Verge will most definitely take you through the best options you can pick today.
Personally, I’d like Dropbox and Evernote to meet halfway: I’d like to have a better file management UI in Evernote, or some lightweight document editing in the Dropbox iOS apps.
If I had to pick one, I’d say better file management options in Evernote (currently, I have 7440 “notes” – but many of them are actually screenshots and PDFs).