So here are some images. You tell me whose the best rendition of each and which one is the one you'd buy.
Optimus Primal:
From left to right, its, e-hobby repaint, Burning Convoy, Robot masters primal, and Takara Reissue primal:

Original Optimus primal:

Reissue Optimus Primal from Takara/TRU 2 Pack:

Robot Master primal left, Takara Reissue Right:

Original Megatron:

Takara/Hasbro 2 pack Reissue Megatron:

Robot masters Left, E-Hobby repaint right:

E-Hobby repaint:

Reissue Megatron left, Robot Masters Right:

Reissue Megatron left, Reimagined Megatron right:

Robot Masters, Reissue, repaint:

Robot masters, Reissue, repaint:

courtesy of Remy at TFKenkon and Seibertron.com
I own the Hasbro 2 Pack reissues 10th anniversary Toys R Us exclusive Optimus primal VS Megatron. Is there any difference between the Japanese Box set and the Toys R us Hasbro exclusive???
I also Own the Takara Beats Wars 10th Anniversary reissues 1 through 9. so far..
I didn't realize that Robot Masters was its own cartoon series, direct to DVD format. the video is on TFKenkon.com..so that explains why Megatron Robot Masters has a Decepticon symbol on his arm..And also why Optimus primal has one on his as well..
