This is just my opinion, but I HATE forums that are cluttered with members using huge emoticons all the time. I'm fine with smilies, sad faces, mad faces, etc. But I HATE those ones where they hold up signs and say sh*t or the ones that are super animated.
IMHO it can make a forum look childish and unprofessional.
With that said, variety is great, and as long as they matched the current ones, I'd have no problem with a few more.