Predator: Concrete Jungle is the best one I've read. IMO it would've made a better Predator 2 than the one we had. Also it's worth reading AvP: Prey at least once. It occasionally has chapters from the preds' p.o.v. spoken in their own tongue, which is a little cheesy but it's still a good story.
I just can't figure out what these guys' problem is. It's like the publisher's running a contest to find the most ridiculous, comedic plot anyone can think of. I could probably wave off one ridiculous novel as being a fluke, but this is getting to be a joke.