I'm looking for an external hard drive for my 15" rMBP. I'm a journalism student, so I will most likely be using it to save lots of documents and a decent amount of pictures, but will also use it to hold DVDs since my computer doesn't have an optical drive. I'd like it to be portable, but an extra half-inch of thickness here or there isn't a big deal to me! Any recommendations? ---------- Another thing: I'd like to not pay an arm and a leg (probably under $100), and would prefer Thunderbolt or 3.0. Thanks!