They are a bloody dictator, diamond smuggler, crack-smoking school teacher, lecherous old man, and self-centered dad. But when it comes to winning an Oscar for best acting, the more human flaws, the better. This year's Oscar nominees for best lead actor -- Forest Whitaker, Leonardo DiCaprio, Ryan Gosling, Peter O'Toole and Will Smith -- portray characters so fault-ridden that they are hard not to like. In fact, Oscar loves them. But who is the front runner, given the history of the accolades that have been dolled out over the past few months? Access Hollywood's film critic Scott Mantz believes it to be Whitaker, who plays the blood-thirsty late Ugandan dictator Idi Amin in "The Last King of Scotland." "He just commanded that performance with such intensity, with such bravado, it was terrifying, but it was almost like, I hate to say it, the kind of bad guy you love to hate. It was a great performance, he's won every award, the Golden Globe, the SAG award, he just won the BAFTA this past weekend, so he's on his way, just like Helen Mirren's won every award," says Mantz. O'Toole, 74, stands the best chance of beating Whitaker, because Oscar voters tend to favor screen veterans regarded as long overdue for an award, pundits say. The Irish performer, who shot to fame as the star of "Lawrence of Arabia," has received eight nominations as best actor in the past four decades without yet winning. In "Venus," he plays an elderly actor with a love of whiskey and a crush on a younger woman. "Don't rule out Peter O'Toole. Here's why -- he's 74 years old, he's never won an Oscar -- it's his eighth nomination, no wins, he did get a Lifetime Achievement Award a few years ago, but Academy members who are older might look at this performance, which was terrific and a deserving performance, they might look at the performance as their way to right all those wrongs, and to give him an acting award to honor his body of work. It happens all the time," says Mantz. Leonardo DiCaprio has been an academy favorite since his best supporting actor nomination for 1993's "What's Eating GIlbert Grape," and was again nominated recently in the best actor category for 2004's "The Aviator." He has come a long way since his role in 1997's "Titanic," avoiding the "Hollywood pretty boy" label by venturing out to take some grittier roles like that of the scheming diamond smuggler in "Blood Diamond," but he may not be in his prime just yet. Furthermore, "Blood Diamond" was a major Hollywood production but it struggled at U.S. box offices with a modest gross of just 55 million U.S dollars. That fact spells trouble for DiCaprio because Oscar voters like blockbuster ticket sales from big-studio movies. "He is someone who does not want to be a poster boy -- he is a serious actor and he does not disappoint. The thing about Leo though is, with 'Gangs of New York' and 'The Aviator,' as great as those performances were, I thought he still looked too young to be playing those roles, the performances were great, but now that he's getting a little older, with 'Blood Diamond' and with 'The Departed,' I think that Leo is finally growing into the roles that he wants to play, so his best is yet to come," says Mantz. Another likable guy to cheer on is Will Smith, who was first nominated for the title role as the world famous heavyweight champion boxer in "Ali" in 2001. His second nomination for best actor in "The Pursuit of Happyness" proved Smith has range in his talents, playing a father with big dreams who plunges himself and toddler son into poverty by taking a non-paying job at a stock brokerage. "It's a great character to root for, he's very likable. I mean, here he is, he's trying to follow this dream while trying to support his kid, who's played by his real son, and I think that really brought out the best in his performance. I think it was a very likable movie, maybe a little too likable, and that might be sort of the backlash against it, it was a little too sweet for a movie that should have been done more gritty," says Mantz. A surprise nomination came this year for relative newcomer Ryan Gosling, whose role as a crack addicted inner-city schoolteacher in "Half Nelson" won accolades at the Sundance Film Festival in January of 2006. However, not many people have seen the film, and it might have had more of a chance if it debuted during any other year when the competition might not be so fierce. "'Half Nelson,' that was another Sundance movie. And when that came out, I mean, it's a great performance, it's the type of performance that no matter how many people have seen it, it has to be honored with an Oscar nomination, but just, you're up against Forrest Whitaker. Sorry, it ain't gonna happen," says Mantz. The Academy awards will be handed out in Hollywood on February 25.