i got 16 gigs and i dont have problem with it. everything is in the cloud.
1. Photos and videos, i use google photos, so no hard copy of photos in videos on my camera roll. and the most important thing of google photos is i can switch device to android and boom, all photos are synced, or i can sometimes miss my 5s, switch simcard, boom, all photos and videos are accessible in 5s.
2. music, i use apple music, but will switch to rdio because it's dirt cheap. and i only put 30-50 offline songs from my itunes in a playlist called "Current Listening". i choose some songs that i currently like and sync it from itunes to my iphone. you dont need a freakin 3000 songs in your pocket don't you?
3. games, this is relative. i do games on PC, so i only have light games in my iphone which is rarely have size more than 100mb each. games like space age, clash of clans, bitcoin billionaire. who needs 2gb of games like final fantasy 7 and nba2k16 while i can experience it better on my PC.
but i believe, the 64gb is the most value in price/storage capacity. i just dont have the budget for 64.