Excellent question. Depends on what you're after. Here are the criteria you can use to help decide:
If you are a Completionist and hate cliffhangers:
Both of her currently-published works are the beginnings of trilogies. She has full contracts for the entire trilogy of both sets of books, but neither trilogy is fully published yet. One of the trilogies (Toby Daye series) has two books published with a third on the way, the other trilogy (Newsflesh Trilogy) has one book published with two more on the way. This award will hopefully help yet another set of Toby books see the light of day (at the very least).
Genres:
Toby Daye series (Rosemary and Rue, A Local Habitation, An Artificial Night), written under her real name of Seanan McGuire: This is urban fantasy, the genre that posits fantasy beings living simultaneously with normal humans. Toby is a faerie living as a human, and she has some mysteries to solve and some life-and-death situations to deal with. The plotting, characters, and detail of these stories is what won her the award yesterday. Two books of this series are complete, the third is on its way.
Newsflesh series (Feed, Deadline, Blackout) written under her pen name of Mira Grant: This is a unique twist on the horror genre: Political horror fiction. Imagine "The West Wing" with zombies. It posits a universe where the zombie apocalypse has come and gone, and the human race survived. But so did the virus that caused the zombie apocalypse in the first place, so people still turn into zombies regularly. Because of the ability for bloggers to get information out faster than conventional news media, blogging and social networks became a cornerstone of society during the zombie uprising, and now blogging carries a great deal of weight. The story follows a group of bloggers who are covering a presidential campaign race, and there are (of course) life-and-death situations for them to deal with and mysteries to solve. This series is most notable for its world-building. Her attention to detail about the changes in social and political culture that would happen in this kind of world is garnering her stellar reviews. Example: In this world, parents tend name their children after the people who were the heroes during the uprising, which of course were the people who taught the world how to defeat zombies. So the main characters are named Georgia (after George Romero), Shaun, and Buffy. That's a funny example, but there are also more serious examples throughout the book, for example, the fact that people don't go out to eat at restaurants any more, they tend to stay shut in. Parties where large numbers of people gather are considered an extravagance, because the chance of one person in the crowd turning to a zombie is too high for most people to risk. That sort of thing. This is the one where there's only one book of the trilogy complete with the second and third on their way.
