There is a designation for top poster. It's been Amma for a while (not sure if it still is...I don't really pay attention to it). Other than that, I don't know if there's a contest or not. I mostly visit the Unread Topics section, so if I'm on I see posts that come on pretty quickly.
Amma beat me to an answer and I see she is still top poster. Not only is she a smart quilter with lots of good advice, she is also fast! :-D :-D