Yeah finding a category that my pictures are mostly about will be a challenge. But to put it simply it would be fandoms generally. And technically that'd be a category. A various one but a category nonetheless.
Mostly family pictures, but that's only because most of the pictures on the computer are my mom's. My personal folders have mostly 迪士尼 characters and 幻影忍者 pictures. XD
Not being specific, a large portion of my pictures are of classic rock stars from the 60's & 70's. Being 更多 specific, my Jimmy Page folder has the most pictures in it.
They are mainly pictures of 日本动漫 and famous shows 或者 actors, haha. For example; Supernatural, Jensen Ackles, Logan Lerman, One Direction, Louis Tomlinson, Ariana Grande, Fairy Tail, Zero no Tsukaima, My Little Monster and screenshots from tumblr, haha. That's a long list, sorry.