John Ringo: Millitary Science Fiction with Some Actual Science in it.

I just finished reading Manxome Foe, the third book in John Ringo's Looking Glass trilogy. The trilogy, which begins with Into the Looking Glass and continued in Vorpal Blade is a military science fiction series dealing with the results of an experiment gone wrong that opens portals to other planets in the galaxy, some of which lead to the worlds of the ravenous Dreen, who wish to overrun Earth and devour or enslave all of humanity.
Premise sounds kind of cheezy, but the stories are solid page turners, that have kept me up until 4am with the dreaded "one more chapter" disease. The characters are interesting for the most part, and there is plenty of action against gribbly space monsters to be exciting.
The big difference in this series is it does insert quite a bit of actual scientific theory into the narrative. The insertion flows naturally, without seeming as if it were "tacked on" to the overarching story.
If you are looking for a series of action books with a little more depth than just monsters being shot in the face, check out this series.