Hmmmm. G1 Optimus Prime is a pretty solid design, though he does have one glaring flaw in the form of that stupid decorative handle (doubly annoying on the retooled reissues because instead of having the sense to turn it into a second peg... HasTak decided to give his fists elevated cups to better grab the existing peg while holding the gun straight.
). Still, a solid toy with plenty of play value. Ditto for Ultra Magnus.
Masterpiece Roddy (the Takara version anyway, not Hasbro's half-the-toy release) is a good design, even though he suffers slightly from Takara's apparent decision that the Masterpiece line didn't necessarily need durable plastic since it's marketed to adult collectors. A big plus to him is that at long last there's a Rodimus Prime big enough to toss G1 Galvatron. Design-wise he has it all over Masterpiece Optimus Prime (either version), Megatron, Ultra Magnus, and Ratchet and Ironhide in my book, being wonderfully accurate in all modes while doing everything his original toys did and then some.
Cybertron Leader-class Optimus Prime is another star design, and extremely rugged to boot. His vehicular flight mode alone is beautiful, and he has an awesome Super Mode. Plenty of firepower, and designed not to impede his articulation overmuch. And the removeable Matrix of Leadership is also neat, even if he can't hold it that well.