I like this one a lot but might be a little too 'fun'. Not sure how to fix that exactly, perhaps make the face closer to something like this:
http://www.willibrorduslagezwaluwe.nl/leerlingen/starnet/media/foto_s/groepen/8/22143-Clipart-Illustration-Of-A-Yellow-Emoticon-Face-Grinning-And-Wearing-Dark-Sunglasses.jpgAlso would be nice to see a different font