Shirt Design for Conventions

I've been considering having some shirts for cons and such, but i am not sure which designs I would want to have at a particular con. I decided to start with my favorite subject matter type: Tentacles! 

HEre are four designs that I'm thinking over right now...which do you think would look best( the blue would be whatever color the shirt is...I havent' decided that just yet. Let me know here on my blog!