>>5721794FE Optimus is my favorite.
It has good articulation, a lot of presence, and zero kibble.
The only downsides are that his shins just hang in there rather than tab into anything, though it has never given me any trouble, and shitty rubber pieces that are just waiting to rot on you no matter how well you take care of it.
I have the issue of not finding a Megatron that is on his level because HasTak tried to be funny with TF:P and made the corresponding FE Megatron a deluxe.