My wife has played all but one of the games in Her Interactive's Nancy Drew adventure game series. I have played a handful of them as well. Then, several months ago, Her Interactive released a new style of Nancy Drew game - a casual-style game called Nancy Drew Dossier. I played through Lights, Camera, Curses once and narrowly missed achieving enough points to gain Master Detective rank, which is required if you want to get the bonus ending. So I played the game again, and it was still fun a second time.
The main mechanic of the game involves going from scene to scene, locating objects, and combining the objects in the right order. Each time you combine the correct items in the correct order, you gain points. The points increase for every additional success. If you mess up, the points start small again. Another big part of the game involves interacting with a cast of voice-acted characters who all seem suspicious in one way or another. During conversations, you are given a list of responses to choose from. If you choose the correct response, you earn points. Finally, there are mini games dispersed throughout the game. They are usually simple puzzle games which allow you to earn more points. As you collect points, your detective ranking increases. If you achieve the rank of Master Detective, you get to watch the secret alternate ending.
I'm really looking forward to the next game in the dossier series. One other feature worth noting was that the music in the game (composed by Matt Sayre) was excellent and perfectly fit the mood of the game. This is still probably my favorite casual game to date, and among my top 3 Nancy Drew games. It's definitely worth trying. Big Fish Games has it for $6.99 which is much less than what you'll pay at the Her Interactive website.
Here are some other Nancy Drew mystery adventure games worth downloading from Big Fish Games: