@Night Rider, if by "fighting knife", we mean a knife carried with the primary intention of being used against live human targets, there are probably more fighting knives than there are fighting styles, and there are a lot of fighting styles. You can even see this trend all the way back to medieval times and further, as there were a variety of secondary and tertiary blades that were used, even when blades were a primary weapon. In this thread, there are examples of my own that include a large work knife, that would double well as a fighting knife if you're not in a context where rifles are likely to be carried. I have also shown a dedicated compact fighting knife meant for combat soldiers who might be at close ranges with the enemy, and a tiny defensive knife meant for troops who might be caught without any weapon, and even perhaps without any clothes! So there are three widely differing knives, with three very different missions, sharing only the characteristic that all of them are designed with ways to help protect the user's hand from slipping onto the blade. Are they all fighting knives?
There is a type of knife that in the US has come to be generically described as a fighter. The Randall Fighting Knife is probably the easiest example of this style knife, what I think of as a "stabby Bowie" with usually a 5 to 7 in or so blade, and single or double guard. Sometimes they have a sharpened false edge.
@Valkman's fighters shown here fall into that category (though with a choil and blade profile designed to protect the user's hand, instead of a guard).
There are also what I think of as deployment blades, which are usually fairly general purpose knives that could also be used for defense at close ranges, if needed. The USMC fighting knife, the quartermaster's knife, the Air Force survival knife, and many others fall into this category.
Fighting knives are knives people carry be used against other people, or potentially animal threats. Himalayan people, to include gurkas, have carried the kukri for many hundreds of years. They have many different styles of kukri, and several are used every year for defense against the local bears, which are small but aggressive. I think knives carried for offense or defense should usually have some protection against slipping onto the blade. The kukri is a notable exception to this rule, in that it is almost completely a chopping knife. My Camp Defender design incorporates a weight-forward style that allows chopping, while also allowing for a stab if desired. It also provides protection for the hand. anyone who handles a Camp Defender will probably not be surprised that I have spent many hours using kukris. I designed a knife that met
my ideal requirements for engaging a dangerous threat at close range. If I couldn't use a knife like mine, my very first choice would be the Spyderco
Darn Dao. The Dao, though, really is edging more into short sword territory than what most of us think of as a knife.
Different people will have different ideas about what makes a perfect/ideal fighting knife. Be safe, train realistically, and make your decisions from there. I suggest full water bottles* and PVC insulation around midsize branches to begin getting an idea how effective YOUR "fighter" might be.
Good luck,
John
*one or two liter full water bottles hanging from 550 cord can move, and provide some resistance against slashes and stabs. If you get good at opening them up safely (swings should stop
just after the target, so you don't leave yourself open for a counter-attack), you can begin taping old clothing to the bottles for additional resistance. Your results may surprise you.