I'm always a sucker for reading books based on games I enjoyed and recently finished the second book in the Mass Effect series written by Drew Karpyshyn, who had written the script for the game and faithfully keeps the world between the books and games exactly the same.
While the first book (Revelation) fleshed out the back story between Captain Anderson and Saren that was briefly mention in the game, the newest story begins shortly after the events of the game.
Returning protagonist Kahlee Sanders is now employed in a school geared toward gifted biotic students and one student in particular, Gillian Grayson is a gifted autistic student who displayed exceptional ability. Meanwhile a shadow organization called Cerebus is keeping tabs on the young girl with operatives on the inside. When the plot is exposed, Kahlee and Gillian go on the run from the organization while figuring out their true intent with the girl.
The story was intriguing enough but for anyone who may be looking for an extension of John Shepard or Captain Anderson will be disappointed. Anderson is only mentioned in passing and Shepard is not at all. The story however provides more backstory about the Quarians and the Migrant Fleet giving you an inside look on their culture and the ending remains open for its obvious sequel.
Overall I would suggest that if the Mass Effect world left you wanting to know more than pick it up and read it but don't be fooled into thinking this has anything to do with whatever you have played already.