Mr. (Isaiah) Edwards from Little House on the Prairie is this trope personified. The books made him that way too, using a variant of the folk song Ol' Dan Tucker as his theme.
Prince Arthur from Merlin, as he often goes hunting or engages in quests with gusto, especially in the beginning of the series.
To an extent, all the Knights of Camelot are like this, apparently. In one scene, Arthur gives Merlin a friendly punch in the arm "to cheer him up", and when Merlin asks why on earth he thought that'd work Arthur replies, baffled, that it always works on the knights. ("Well, they're a bit thick, aren't they?")
Gwaine deserves special mention. He's extroverted, charming, loves to have a good time, and is an undisputed Bad Ass.