You ever look into Western Digital My Passport drives? They come in sizes up to 4 TB, but have a pretty small footprint.
Using one currently, and they frequently go under $100. Works wonderfully, very small, would store easily if for some reason you didn't want to leave it hooked up to a console or needed to transfer between multiple systems. My only complaint now is that my 4TB is filling up, and I refuse to buy any USB storage with external power.