Boss Nass, the Gungan head honcho from Star Wars Episode I. His booming voice and seizure-like expressions of displeasure make him more expressive than most of the human cast. The character was written as a strict, xenophobic no-nonsense ruler with little patience, who eventually had a change of heart when he realizes he's misjudged the race he despises, and becomes friendly and joyful. Blessed's performance changed the characterization.
Every character that Alan Hale Sr. did. His son Alan Hale Jr. did this as well early in his career. But as he aged he was casted more and more as a villain. Which is why he took the role of the Skipper in Gilligan's Island , he was tired of playing bad guys.
You could argue that El Indio from For a Few Dollars More is a deconstruction of this trope. He laughs all the time, hugs his friends a lot, is enthusiastic and boisterous and runs a band of plucky outlaws out to rob an impenetrable bank against all the odds — but he's a depraved child-murdering, stalking rapist and his band are all implied to be similarly bad. His happy laughing face gets on his Wanted Poster, but he also has a much more evil, violent side to him which causes him to turn on his own men. Lastly, his good moods seem almost maniacal, and are probably induced with drugs.
For Your Eyes Only and Colombo, arguably a thinner version of the character. Played by Topol.
Antaeus the bully bandit from Hercules Unchained, featured in MST3K. At one point Crow even wishes that he was on the heroes' side, since he seemed a lot more fun than the real hero, Hercules (who seemed to spend most of the movie either sleeping or acting like a total crab).
Ray Winstone as Bors in the otherwise lame King Arthur (2004) film. Cheerful, savage, so many children he just gives them numbers... Ray Stevenson was also awesome as Dagonet. All the knights were like this to some extent, apart from Tristan and Arthur himself. The scenes with them cracking jokes at each other are easily the best parts of the movie.