I'm currently reading MASS EFFECT: Revelation by Drew Karpyshyn. Modern Sci Fi can sometimes be tortuous to read and best done in some darkened cloister beacuse it feels like a badass hangover. Not so MASS EFFECT: Revelation, instead I found it easy going and a good read for the train. It's scarily engrossing. I passed two stops without noticing and the train pulled into Aberdeen in a blink of an eye as a result.
You don't have to know the MASS EFFECT universe to enjoy the book, and I'm thankful that it doesn't try to force it by overloading your brain cortexes with leaden descriptions of everything. Certainly having played MASS EFFECT on the XBOX360 to the point where it was going to be cited as the other party in a divorce, I probably am enjoying the book more because I'm familiar with the visual imagery.
The storyline revolves around an attack on a research station by Mercs and the resulting search for a missing scientist. It does fill in the back story of MASS EFFECT as it goes along and provides a decent prequel to the game.
It's by no means in the same league as Forever War or Starship Troopers, but it's an enjoyable military Sci Fi read nevertheless and has given me some plot ideas for a couple of Sci Fi skirmish games.