I think the hammer is the best one. It is powerful and has the empty space the cans one is lacking.
But I think all the elemnts are competing a little too much. There might be too much textured stuff going on. And the gradients are only adding to the mess.
The letters could use some more letterspace since they are all caps. Although that would break your idea of a solid block.
I think the spraypaint package is more representative of your style, although a combination of the spraypaint imagery with the sledgehammer's cement/asphalt-style font design might better suit the smashmethod monicker.
I also like the suggestion of the CMYK color palette with the spray cans - but only if you intend to do more print work. I'd also consider putting one of your chaotic collages on the flipside, and leaving off the "http://" as it makes your website easier to read and browsers don't require it anymore. There's a great control of typography in all of them.
I still like the crest design, but unfortunatly it has become generic.