Some people love River Song, and some people despise her very name. Unfortunately though, while I can't sit back and defend every single line of dialogue she's ever had - it's completely subjective, and you're within your right mind to hate her - I can mention that the very essence of the character is written with the best of intentions. River's maybe the first character since Romana, actually written as a female friend of the Doctor, who's his equal. Not just his lover, his best friend, or his ultimate companion, but as good in every respect as the Doctor: more than his match. But actually, that's not why she's great: Alex Kingston was 50 last year. How many 50-year-olds have a huge role as a love interest in any TV show or film? Especially if the male is twenty years younger? River is a role model to younger women, and older women: she's not just any middle-aged, stay-at-home wife, she's an Indiana Jones-style time traveller, and she embraces looking good and having fun. And remember how excited she was when she regenerated into an older woman? From a non-white girl: also a first in Doctor Who. That's laid the foundations for the Doctor to not always be caucasian.