Yesterday I mentioned my agent's report that she's having a hard time selling books with difficult main characters, that publishers seem to be looking for nicer, more sympathetic people. Although there was much outcry in her blog comments about how sick people are of perfect, flawless characters who have no room to grow, I don't think that's necessarily what's going on. I mentioned a couple of ways to make nice people interesting. There are also a lot of examples currently on TV. I guess the nice guy trend is hitting there, too, but mostly with men.
Using archetype terms, the Best Friend is usually the sidekick character, the loyal, faithful friend you can count on and who tries to keep the peace, maintaining harmony, morale and good feelings around the group. For traditional uses of this archetype, we've got Xander on Buffy and Wash on Firefly, or Ron Weasley in the Harry Potter books. This is one of my favorite character types, and we're now seeing it used in some unconventional ways as the Best Friend steps up and starts to take the lead.
I guess one of the more conventional Best Friends on TV today is Jim on The Office. He's kind of the sidekick in the sense that Michael is the main character and gets higher billing, but in story terms, I would say that Jim is actually the protagonist. He's the one set up for the audience to identify with, and he's the one who seems to have a character growth arc (while I don't think Michael will change all that much). Jim is the one the documentary crew seems to have latched onto, and I get the feeling that the documentary within the show is essentially telling Jim's story. Jim is the nice guy who can build office morale and who looks after his co-workers -- even though he usually picks on Dwight, he's been trying to help Dwight through the pain of a break-up. He's certainly not perfect, as he does play pranks that verge on meanness, and he's stuck in a rut professionally. He hates what he does and where he is, but he doesn't seem motivated to do anything about it or even explore what he does want to do. The other thing that makes this nice guy interesting as a protagonist is the fact that he's surrounded by crazy people. It's the "center and eccentrics" comedy model, where Jim and Pam are the only two sane people in a crazy world. That creates contrast, which creates tension and conflict. If you want to have a nice, normal main character, put him in a crazy situation surrounded by oddballs. You can also give him an area of doubt and uncertainty, something he needs to change about his life, which can be what kicks off the story.
For another fun bit of contrast, we have Earl on My Name is Earl, who is a reformed Bad Boy turned Best Friend with his discovery of karma. We get contrast and conflict because he's got a Bad Boy past and a Best Friend conscience, and he's still dealing with the consequences of his past because he's surrounded by the people who were in his life when he was a Bad Boy. Though Earl is far from "normal," this is also kind of a center and eccentrics model, where the people around him are even stranger and he's often the voice of sanity and reason. There's another way to make a nice guy interesting: give him a very non-nice past that he's moved on from, but with consequences he can't escape.
We get the Best Friend as action hero in Chuck, with the guy who just wants to be a good friend and a good brother being forced into international espionage and intrigue. This scenario wouldn't work as well with a different character type because a lot of the conflict and tension in Chuck's life comes from the fact that he is loyal to his country and wants to help stop the bad guys, but he also doesn't want to let down his friends or his sister. A Warrior type would ditch it all to take on the mission for the greater good, but a Best Friend tries to find that balance, with what are sometimes mutually exclusive goals. So, there's another way to make the nice guy interesting: give him an important task to do that conflicts with the things that are important to him as a person.
For another Best Friend as action hero, with a side of angst, there's Sam Winchester in Supernatural. Although he's up against big-E Evil, his focus manages to stay on goals closer to him -- first, finding his father, then along the way helping the individuals they meet who need help, and now trying to save his brother's soul. What gets interesting with him is that he isn't evolving to a different type now that he's up against bigger and worse things. He's retaining his essential nature, and that means the things he's having to do to save the day are tearing him apart inside. Being a good brother may mean having to do things he otherwise wouldn't do. Again, there are the mutually exclusive goals and needs, where finding the harmony the Best Friend seeks means doing the kinds of things Best Friends usually don't do, like killing and dealing with darkness. Want to make a boy-next-door type suddenly fascinating? Send him way the hell away from Kansas (come to think of it, literally in this case) and put him in a situation where you wouldn't expect a nice guy to survive. (And speaking of Supernatural, can we have an episode where they find and slay the evil demon who wrote that "Be Brave, Not Beige" Ikea commercial? Because whoever did that has to be a minion of Satan and pure evil, working to invade and control the brains of the entire population. Make it stop!!!!!!)
This is still a little new for me to have a strong sense of the character, but I'm thinking Charlie Crews on Life might also fit this type. He's got a lot of Best Friend traits, in that he gathers people around him in a kind of made-up family, sides with the underdog, and gives people second chances. He has a convicted white-collar criminal living in his garage apartment and handling his finances, which is the kind of trust you'd only see from a Best Friend. But he's a nice guy who's been damaged by being wrongfully convicted of (and probably framed for) a crime he didn't commit, and having spent all that time in prison. He kept his sanity in prison by trying to find inner peace, but he also learned a degree of ruthlessness. Our interesting nice guy lesson here is that giving him a difficult experience in his past can give him an edge without changing his essential nature.
I'm still trying to figure out Ned on Pushing Daisies. My guess is that he's inherently a Best Friend, but all the fallout from his gift/curse and what it did to his family and subsequently his life have turned him into something of a Lost Soul. Charlotte (I'm trying to avoid confusion here with the other Chucks on TV) brings out the Best Friend in him, and it's possible that he's finding that part of himself again through her. Normally, he avoids contact and closeness, but he's blossoming under her influence, which kind of parallels him literally bringing her back to life. A tragic past works wonders for making a nice guy fascinating.
Another one I'm not sure of is Mick on Moonlight, who seems to be a boy-next-door vampire. He doesn't seem to have any grand anti-evil agenda. He just wants to help his clients, and not all of his cases have anything to do with him being a vampire. He's not crazy about being a vampire, but he isn't too mopey about it, instead treating his vampirism as more or less an inconvenient medical condition. I'm not yet sure how well that's going to work as a series, but it's definitely a different approach to vampires, who are usually Lost Soul, Warrior, Bad Boy or Charmer types. I suspect that a Best Friend vampire who bucks all those usual vampire expectations would have worked better in a more comedic show, say if the female sidekick had read too many of the sexy vampire paranormal romances and was constantly disappointed by the real thing being a bit too normal. They played with that some in Angel, but he was still the Lost Soul/Warrior type and not too far from the usual vampire hero, so they didn't go as far with the joke as they could have.
Moving away from TV, I don't even think that a flawless, perfect character is necessarily boring. Take Carrot in Terry Pratchett's Discworld series. The whole point of that character is that he's essentially perfect -- he's handsome, good, totally incorruptible, brave, and honest. His only real flaw is that he's so perfect, he doesn't understand that other people aren't as naturally good as he is -- but then people tend to live up to his expectations of them. I think he's a fascinating character because of the effect he has on other people. The fact that he's the rightful king and doesn't want the throne helps with the intrigue, but still, he's proof that it is possible to write a nice, good, perfect character without him being boring. It does help that he's surrounded by very corrupt people, so his goodness is a contrast. You wouldn't want him in a story full of essentially good people.
I think the same tricks would work on female characters, but it's a more difficult situation there because the nice girl is a more conventional heroine, while the nice guy is kind of different being moved from sidekick to hero. With women, it seems like it's either the tough, kick-ass heroine or the sweet sidekick, rather than the sweet girl who is thrown into a situation where she has to kick ass. Maybe I don't watch enough shows with central female characters, but sorry, I happen to enjoy watching men a lot more, especially now that they all seem to be just my type.