If by that, you mean from the 4th film, bloodied, covered in smoke, mud, etc. big machetted in hand, rage on his face, then the most BADASS statue ever. Or even FB 2 with the bow . While First Blood is classic and iconic, there's no really great statue poses you could really get from that, but anything from 2, 3 or 4 with weapon in hand and fury in his portrait would make a great statue.
I'd like a Rambo from any of the films but, imho, the most competely iconic version would be the RAMBO: FIRST BLOOD PART II incarnation with the redhead band and Co's necklace holding the M-60. Then the exclusive could be interchangeable arms holding the bow.