I haven't read any Aliens novels in a while. I've heard that Tim Lebbon's trilogy, beginning with Out of the Shadows, is very good, and I'm very curious about the Rage War trilogy (which also involves Predators).
I read most of the Bantam novels in the 90s, and they were, with one or two exceptions, novelizations of the Dark Horse Comics series. They were okay.
I read some of the Dark Horse Aliens novels. Michael Jan Friedman's Original Sin was pretty good; it's a sequel to Alien Resurrection and it reads, basically, like a Firefly novel would have. It has that kind of plot.