The answer is: it depends. Okay, it is not conclusive, but in reality yes, it truly depends on many things. This is purely my opinion regarding the storage usage.
For normal user who uses notebook as both for working and entertainment, I guess 500 GB is enough. Enough to store most pictures from the phones/DSLR camera, movies, musics, works (sync with cloud storage), software for works, installer, and last but not the least: games. Games and movies will take a lot of space.
For average, a 720p movies will roughly takes around 1.6 – 4 GB of HDD. A game, on the other hands, on average AAA games, will takes around 5-15 GB. A HDD is preferable because of the price. SSD 480 GB equals to the price of 3 x 2 TB HDD . Ultrabook, however, relies on the SSD to reduce dimension.
>> 500 GB is enough and practical
Mobile devices storage usage is quite segmented, usually ranging from as low as 8 GB until 64 GB. My experience told me that even 16 GB is just too small to store anything in the phone. 32 GB is just right and 64 is safe. Phone with 128 GB internal memory? That’s ridiculous, it will be too expensive to make. Most Android phones have support for SD Card expansion (up to 128 GB SD Card), although in reality it doesn’t help that much. SD Card is considered as secondary storage rather than part of file system, which usually makes it impossible to install apps exclusively in SD card.
Storage in mobile phones are usually used for pics, videos, music, and games. Since mobile games growing rapidly, several console-quality games appear in mobile platform with their ridiculous size (compared to “casual” games), almost equals with the size of the console counterpart. Several games now takes a lot of space, say 500 MB – 2.5 GB.
>> 32 GB is enough and practical. 64 GB can be quite pricey, but it is a safe bet.
Usually people do not consider this as a significant factor. However, cloud storage has become the bridge which connecting both notebook – mobile devices. Not for long, your cloud storage will be filled with the files from the office, pictures taken with the phone, and several items you want to sync across the devices.
With pictures piling up in the dropbox, works, projects, etc., 16 GB of cloud storage is a safe measure. The first 5-6 GB will be used for phone-related syncing items, 4 GB for picture backup form the local computers, and the rest will be used for rescuing your important files in case of the unwanted occurs.
>> Dropbox? Invite many person to hit the cap of 16 GB.
This one is purely optional, especially if you’re a PC gamer. The current generation only sporting the default 500 GB of HDD with usable only 400 GB. The problem: those blu-ray games takes 35 GB++ in HDD. On average, a gameplay footage takes 800 MB. 500 GB is not enough. 1 TB maybe safe for 1 year, but no more than 1 year, especially if you buy often.
>> 1 TB with a lot of uninstall for years.