Reddit mentions of All You Need Is Kill

It was a good film. If you liked it, you have to check out the short novel it was based on, ["All You Need is Kill"] (http://www.amazon.com/All-You-Need-Is-Kill-ebook/dp/B005LJETYI).

There is also a [manga] (http://www.amazon.com/All-Need-Kill-Vol-manga-ebook/dp/B00KO85D96/ref=sr_1_1?s=books&ie=UTF8&qid=1413527745&sr=1-1&keywords=all+you+need+is+kill+manga) currently being serialized.

The story is much tighter and focuses a lot more on the relationship between Keiji (Cage, in the movie) and Rita. That's all I'm going to say about it for fear of spoilers.

Edit; corrected my tenses.

Player of Games is a good book, and it's early enough in the Culture series that Banks hadn't yet realized he made the Minds too powerful and doesn't need the human characters to actually do anything. But it is not military science fiction and I don't think it's similar to The Forever War.

If you're looking for more military sci-fi I can recommend Forging Zero, All You Need is Kill, David Weber's Honor Harrington series, Orphanage...and many more I'm sure. Armor is great and I'm sure you've heard of Starship Troopers.

A note on David Weber, I find his overuse of italics a constant irritation when reading his books. It really helps to get digital copies and run them through calibre to eliminate all the italics first.

All you need is kill - http://www.amazon.com/All-You-Need-Is-Kill-ebook/dp/B005LJETYI

Then watch Edge of Tomorrow

The book is fantastic and is different from the movie. Check it out: https://www.amazon.com/gp/aw/d/B005LJETYI/ref=aw_ss_kndl_dp/

Try "All You Need is Kill" by Hiroshi Sakurazaka. Japanese, and very science fiction explody with guns and mecha. Although not the main character, has a strong female character in it. Tom Cruise's movie "The Edge of Tomorrow" was based on this book, but don't tell her that.

Also try "I am not a Serial Killer" by Dan Wells. It is about a teenage psychopath that follows a strict code so that he won't become a serial killer. Code works well until crazy shit starts popping off. Has Horror elements, and Wells does a good job of getting in the head of a person that emotionally detached from everyone.

Both are relatively short, and are easy fast reads but super entertaining.

All You Need Is Kill

Mardock Scramble is a pretty good cyberpunk novel.

Seconding recommendation for Crest of the Stars, but the new translation is not quite ready yet. Volume one is only getting released next month and then you can either wait for volumes 2 and 3, or pay for subscription at J-Novel Club website to read the ongoing translation. Or you can wait till all 3 volumes are finished and binge it then.
Banner of the Stars translation will start after they are done with the Crest.

By the way, all titles mentioned above are regular Japanese novels, rather than light novels. It's pretty rare for pure sci-fi to be published as a light novel.

As for magitek/science fantasy, Owari no Chronicle is quite good. It's only available as fan-translation, you can find it at Baka-Tsuki. And there's an informative review at MAL.

https://www.amazon.com/All-Need-Kill-Hiroshi-Sakurazaka-ebook/dp/B005LJETYI/