My favorite fictional character from anything ever is a guy from something I don't think I can post on PC.
His name is Gian Carlo. He's from a Visual Novel. I love him because he's the most "I don't really care at all. No, really. I don't give a crap" person I've ever seen, but at the same time, he's so happy. He teases people, he has the highest pitched voice out of everyone (minus one, who has no strength in his voice at all), and best of all, he has almost no sense of hygiene and he gets called out on it. How realistic of him. Basically, he's carefree and happy.
But also, he's a Mafia boss, so when he has to get down to business, he gets down to business.
And that's basically the kind of character I like. Happy-go-lucky, but serious when and only when needed.