*grins* Seeing that the Vampire genre ratings examples go from Bunnicula to Anita Blake is way funnier than it probably should be.
I personally prefer MPAA ratings because I'm familiar with them, comfortable with them, and have a general idea of what content an "R" fic will contain vs. an "NC-17" fic, but since my main interest with ratings is knowing if there will be much in the way of violence (as a h/c fan, I of course hope for "yes") and whether there will be explicit sex (so I can gauge whether I should access the fic/art/etc. on a public computer or on my parents computer or only on my own laptop), a rating of worksafe vs. mature/explicit would still let me decide whether or not to click on a fic.
Well, as long as people actually typed out the entire word and didn't make me try to parse confusing acronyms like FRNSFWWTFBBQ.