16GB phone
Honestly, these shouldn't even exist. There's no way you can download any more than 10 apps, give or take. 32GB is preferable although that can run out just as quickly if you're not careful. 64GB is just where you want it, and 128GB is godsent.
"I have a 16GB phone and it keeps telling me that it's ran out of storage, and so I deleted everything I possibly could and it's still saying that! I need to upgrade to 64GB or 128GB soon."