It really depends on your budget. In factory or semi-custom knives, TOPS and the Ontario RAT series are good buys. These two brands are very popular with the military in general and with Special Forces too. The AG Russell brand knives are usually good items, and they sell Bob Dozier knives as well. Probably one of the best deals out there. Not cheap, but still a good value for what you get.
Steels to look for are: stainless--440C, AUS-8, ATS-34, 154CPM, VG-10, S30V, and there are other exotic stainless steels that are also very good. The more exotic the steel, the higher the cost. Also, don't overlook the carbon steels like A-2, D-2, 1095, and 1084. I'ver used knives with all of these steels and have been more than happy. Most of the knives I've seen made of 1084 have been large knives for camp use or chopping. If the heat treat is right and the blade is ground correctly, all of these steels will hold an excellent edge. Some are easier to touch up than others.
Knives are kind of like optics---you get what you pay for most of the time. Cheap knives have cheap steel that won't hold an edge very well, and can be difficult to even get a good edge on the blade.