The Seagate 2TB USB 3.0 External Drive is a good cost conscious choice for 2TB of raw storage. Currently Seagate comes as a no-nonsense traditional storage device, while other manufacturers are focused on expanding the services they sell on top of just the drive, expanding the capabilities and functionality for their owners.
Though comparable in size, the Western Digital MyBook Live Drive has a lot more going for it and has more of the aforementioned functionality. Western Digital drives have traditionally outperformed Seagate drives of the same spindle speed but I won't get into that debate here. The Western Digital MyBook Live 2TB USB Drive also has a SmartPhone/Table App that will give your device access to your own personal storage on the go. Well worth the extra cost.
An Android App is now developed for the Western Digial MyBook Live product, your files stored on this device can now be available from anywhere you might need access to them, much the same way DropBox now functions but completely on your own secure devie.