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. Bob Tourtellotte reports.