I have the stainless half-serrated "Next Generation" Ka Bar that was discontinued about 4 or 5 years ago.
I also have a heavily abused (but completely functional) brown leather Ka Bar, a green plain edge Ka Bar, and two D2 steel Ka Bar knives with straight, non-serrated edges. One came out briefly about 20 years ago for a short time, and one was a recent re-issue. I have a few others.
I am looking to add the blue "Space Force" Ka Bar to my collection, but I can't justify the expense right now. I also want to add the desert tan model, as I feel that they may be sought-after collectors' items after they get discontinued.