An attractive woman who is liked strictly for her looks, but once discovered she can read is elevated to a whole new level of hottness.
A reader too, what a double threat...
Someone who has read the books of a popular movie or TV series. These people will generally laud it over "watchers" with comments like "I knew that was going to happen" or "it was way better in the book" or "If you think this is good, you should read the books"
They can generally be spotted as being the ones pulling out their camera phones to record "reaction videos" at a crucial moment during a critical episode of a movie or TV episode (a la the Game of Thrones 'Red Wedding' reaction video phenom) -- thus generally giving away to the "lesser people" that shit is about to get hectic.
Don't be that guy.
How can you tell if someone is a reader?
DON'T WORRY, THEY'LL TELL YOU.