Nancy Drew is a teen detective who was first introduced in books in the 1930s. The books have been translated to various languages, including Braille. The author was Carolyn Keene, and over 100 books have been written from the 30s to the 90s (though not all by the same author, some from various series). Several of the games are based off books.
Nancy's two best friends are cousins Bess Marvin and George Fayne, and they are commonly found in the books and games. Her father, Carson, is a lawyer, and because her mother died when she was only three, they have a housekeeper named Hannah Gruen. Nancy and her family and friends live in the (fictional) town of River Heights. Her boyfriend is Ned Nickerson, and though the two have never kissed in the books, they still remain very close and loyal to each other. Carson gave her the famous blue roadster that appears in several of the books and in the latest movie starring Emma Roberts.
TV shows were also made following Nancy in the 1970s, as well as the Hardy Boys (Frank and Joe). Some made-for-TV movies also showed up, one of my favorites being in 2002 starring Maggie Lawson. The latest one stars Emma Roberts, though I found it to be disappointing since it took place away from River Heights and only Ned was really in it, not Bess and George, and the role seemed to be too childish for the sleuth we all know and love.