This one:
[img ]http://www.danger-man.co.uk/images/portmeirion/hercules.jpg[/img]
Actually, I think this is the most impressive Hercules pic, even if Reeves is smaller than Parks, Ferrigno and Arnold. (Unfortunately, I can't find a bigger, better version of it online.)

It cuts out the two men standing besides him, but I think it is what sold Reeves as Hercules to the public back in the 50s and 60s. Compared to the other two men, Reeves truly looks like a god among men.
Here's thumbnails of more Hercules bodybuilders from Brian's Drive in Theater site:
http://images.google.com/images?hl=en&lr=&client=googlet&q=+site:www.briansdriveintheater.com+hercules