OpenDrive gives you the most online space for free -- but I occasionally encountered problems when trying to sync/upload files that were a couple of megabytes in size through its Java-based desktop client.
Between Dropbox and ZumoDrive, it's pretty much a draw. If you have colleagues or friends who already use Dropbox, that could give it the edge. Still, you may want to check out ZumoDrive and open a free account, since its desktop client includes built-in features that make it convenient and easy to share your media among your various devices.
Howard Wen reports on technology news, trends and products as a frequent contributor to Computerworld and Network World.