people either love or hate the close quarters trilogy.
legend of the jade pheonix trilogy; Look, the clans are a massively screwed up society that a lot of people find offensive; basically rubber forehead aliens, sans forehead. If you can get past that, it is a decent trio of books. But as with Close quarters, I'd get the first book and see if it's up your alley before getting the other two.
Wolf Pack. If you liked wolves on the border this is just a tier below, and above most of the rest.
After Natural Selection come Assumption of risk and bred for war. They're pretty good, if fairly massive, but after that the quality drops.
Test of vengeance, Initiation to War, roar of honor among the later books.