Grimlock
In Transformers, he is the Leader of the Dinobots.  He is one of the most powerful Autobots.

There are two distinct interpretations of Grimlock:

In the cartoon series, he is a strong but dumb "comedy" character.

In the comics, and especially in Simon Furman's version of him, he is a born warrior and hardman, who has a very different approach to leadership to Optimus Prime.  He believes that Prime's compassion prevents the Autobots from defeating the Decepticons.  He looks down on those he considers inferior, but is fearless in battle.
Although arrogant and stubborn, Grimlock is a highly effective leader.  He is an anti-hero, a cross between Wolverine and Leonidas.
"Optimus Prime is too soft, if Grimlock were our leader, we could have won this war long ago!"

"Me Grimlock, Badass!"