Right now (and they’re going pretty quickly) Amazon is having a Gold Box Deal on the Seagate Backup Plus 1 TB USB 3.0 Portable External Hard Drive for Mac. The Backup Plus 1 also allows you to install the downloadable HFS+ driver for PC and use the drive interchangeably between Mac computers and PC’s without reformatting. There is 1 TB of storage capacity with fast USB 3.0 transfer speed and an upgrade to Thunderbolt or FireWire 800 available with adapter, purchased separately.

Seagate Backup Plus 1 TB USB 3.0 Portable External Hard Drive for Mac