#3 is the winner out that lot - its a shame its mostly out of focus - you seem to have locked onto the edge of the shell.
You can do 2 things with this sort of stuff - either narrow DOF, in which case choose your focus point carefully. Or alternatively, because you should be using a tripod, go for a high f number and a slow shutter speed. That way its all sharp.
I'm afraid the composition on the others isn't interesting enough.