This is something very important to be a good competitive bodybuilder.
Serge Nubret- His 3/4 relax pose
Sergio Olivia- Arms over head
Frank Zane- His Vacuum pose is still the best out there
Flex Wheeler- His Back double Biceps due to his back thickness and muscle shape is unique
Lee Priest- His Arm over head is unique, smae pose as Sergio but magnificent in a different way
Bob Paris- his 3/4 kneeing pose, Shawn Ray in the same pose look quite good too
Nowadays, bodybuilders seldom have any signature pose any more.