Presenting Optimus Prime from the Transformers Cybetron animated series. The Cybertron Optimus Prime is actually my favorite Prime - even if I thought that the cartoon was a weird escalating see-saw battle of egos.
I'm partial to the Cybetron Optimus Prime because of his very concept - his looks, articulation and this particular Leader of the Autobot's ability to merge with his fellow Autobots to become a stronger amalgamation. Add a Cyberkey or two and he becomes even stronger. It also helps that he starts out looking like a typical foot-soldier then ends up looking like a futuristic Samurai Warlord.
Cybertron Optimus Prime's Blister car reads: "Optimus Prime is a leader in the best sense of the word, taking point on every mission and never sending his team into any situation he wouldn’t go into himself. Dedicated to the protection of all life and the preservation of freedom for all sentient beings, he serves as a role model for his fellow Autobots. It is through his keen intelligence, even hand, steady nerves and endless compassion that the AUTOBOTS continue to frustrate the evil plans of DECEPTICON again and again. Unlock the power! Super-sized OPTIMUS PRIME figure is battle-ready three different ways! Change from robot warrior to heavily armored super robot and then to a futuristic missile-launching long-hauler! Electronic lights and sounds juice up the action! Activate tons of special features with the AUTOBOT Leader Planet Key—reveal the heavy ION blaster or snap out hidden twin rocket launchers! Place this awesome figure at the front of your AUTOBOT ranks to fend off the evil DECEPTICONS. . . it’s going to be a fight to the finish to save CYBERTRON!"