The forth one looks good. Chalice pics would win a contest here, but you have a different audience on the other forum, if you know what I mean. If you go with a chalice, I like the last one the best.
The first shot is the most in focus and has the eye in a good position. Photowise, I like it the most. It also helps that the frag plug is hidden.
The coral in the last photo looks the coolest to me, but it's focus is on the back edge of the coral. I'd try another shot of the last coral and get the upper right eye in focus.
The focus is not very sharp in any of them. I agree with cparka that the first one has potential, but it needs considerably more depth of field to get more of the coral in focus. The second shot is OK if it were in better focus overall and the frag plug wasn't showing. That air bubble needs to be cloned out as it's a major distraction. The third shot needs to be focused, brightened up and my guess is that the white balance is not right. Good angle and decent composition on the fourth shot, but it's unlikely your camera can deliver sufficient depth of field to make the shot work. The last shot has potential to be the best, by far, but, as cparka stated, the focus is on the back edge and not particularly sharp. If you could get considerably more depth of field and better focus on that one, it would be the standout of the bunch. Also, when shooting these, turn your flow off so feeding tentacles will be relatively still and you won't get particles causing streaks in the image.