For me the first one is the best. The stone looks really heavy. Its so heavy it compresses the text beneath it.
The second one looks like it could be interpreted as a miniature gorilla holding an orange bosuball. Stone looks very light. Now maybe that is the concept, like the gorilla is just that strong, but it seems kind of a reach. Don't they say simplicity is the hallmark of good design?
The third one the silvery ball disappears into his chest but the gorilla does look pretty badass.
4 seems perhaps humorous? Gorilla looks very cartoonish but the action of placing the stone is nice.