Just finished:

All You Need is Kill - Of the 2 movies and this, this has by far the most compelling ending. I don't really like how the time loop thing is handled but the mechanics aren't the most important to the story

Will Destroy the Galaxy for Cash - I love this series. If you're looking for a modern day Douglas Adams this is pretty close

In progress:

Diaspora by Greg Eden - Woof, this starts dense and I don't have the impression it's going to get easier. I'm curious how challenging it will get. Still, it's a fun start for the story