Building characters that are truly three dimensional is a skill that not all writers have. These are just my opinions as an avid reader, but it is also a goal I strive to achieve as a writer. Some examples are Ernest Hemingway's MC in For Whom the Bell Tolls. I love his sparse writing and the MC became for me a very masculine, mysterious, REAL person, someone I continued to think about after I put the book down. I was disturbed and emotional, feelings that you have if it has become real to you. In the book Anna Karenina, the author also created very diverse, real people in his descriptions. I thought it was very impressive how he could jump around from the different characters, male and female, and give such a believable description of their actions, behavior, and dialogue.
Another one is Jane Austen, which is why she is so timeless. Even though she wrote about a society from so long ago, you can still relate to people in her books. For example, in Emma, the character who is sweet but talks too much about nothing in particular. Don't we all know someone like that?
How do you make your characters believable? Are there authors that you consider role models in this area?