Western Digital Elements Portable Portable External Hard Drive 2.5 "Extra Slim USB 3.0 / USB 2.0 1TB Black (Accessory)
Fast, quiet, heated very little, not bulky, cheap and pretty. Nothing but good! Beware, however: 3 USB cables are stiff and will disconnect without warning at the slightest movement, and this can have fatal consequences if the disk is being written!