The Sigma Force series by James Rollins is really badass. There's like 8 or 9 in the series so it'll keep you going for a while.
Lone Survivor by Marcus Latrell. It's a true story about a SEAL team that gets jumped by hundreds of Taliban and does a damn good job of fighting them off, but the author is the only one that makes it out, he was badly injured and crawled for days in the desert before coming to a town that risked pretty much everything they had to hide him.
I just finished Ender's Game a few weeks ago, it was a really good read.