After one Hollywood attempt to bring Nancy Drew to life in the 1930s with a series of 4 Warner Brothers Nancy Drew films, Nancy Drew finally debuted on TV in 1977 with actress Pamela Sue Martin starring as Nancy Drew. She's the closest incarnation of a classic book characterization of Nancy Drew from all the various movies and TV show attempts over the years. This is one reason this was the most popular attempt at Nancy Drew--and it succeeded, for a short time anyhow.
After a first season with separate Nancy Drew shows alternating with the Hardy Boys, in the second season, they began combining Nancy Drew with the Hardy Boys. That didn't sit well with Pamela, so she left the show eventually and was replaced by Janet Louise Johnson for a few shows before the character vanished from the rest of the season and was not in the third season.
While she wasn't blond like book Nancy, a rather superficial criticism at best, she did espouse the pluck, bravery and determination to solve a case no matter the odds that was so evocative of book Nancy. The mysteries also involved similar things to the books and were overall "safe and sane."
Got Clues? Hollywood: Anyone in the future creating a Nancy Drew movie or TV show, would be wise to remember that book Nancy is popular for a reason. After all, she's celebrating her 85th anniversary this year and is still in print! So, straying too far from that formula is unwise--and this has consistently been proven time and time again with all the failures of trying to bring Nancy Drew to TV or movies over the years. Each and every time, outside of the 1970s TV show, that a new attempt at bringing Nancy Drew to TV or movies has been done, someone has used their "creative license" (as in, hey let's screw it up why don't we!) to muck it up and fans have not supported it overall. Bottom line: You can't radically change the character or the formula and expect any success. Further, you can't have a successful TV show or movie without most of the fan base supporting it.
Who else, for something so specific and niche as a character like Nancy Drew, is going to be your target audience for a TV show or movie? Hmm, to clue you in, that would be...Nancy Drew fans! And for further clues, why are there Nancy Drew fans? That's right, because of the popular series of mystery books and games out there. It's not rocket science, Hollywood! :-)