It entirely depends on your needs. If you don't use many apps and don't take many photos or videos, you might get away with having just 64GB. But if you take lots of videos, download a lot of music, and play many video games, you want at least 128GB. Heavy phone users may want to look at 256GB and even 512GB storage options. Keep in mind that a phone's operating system uses up a lot of space, so you're getting less than the storage advertised when you buy a new device.