So what makes a good survival knife? There's a 1,000 different ways to answer that question, most of the answers are wrong or situation specific.
If we start looking for an actual survival knife* we can try and narrow things down a little. A good way to start is to look at the following:
1. Price - you don't want anything that will break the bank. If you have $500 to spend on a custom knife, that's great for you, but most of us don't. Spending beyond your means is also a great way to get a knife you are too scared to use! It's also better to have more than one knife, ideally you'd like to have several stashed in convenient locations, so it's best to look for something affordable.
2. Quality - you want something durable, reliable, and good enough to do the job. The good enough is key, you don't want to run too far afoul of #1.
3. Weight - if it's too heavy, you probably won't carry it or have it when you need it.
4. Carry options - something that you can wear around your neck, on your belt, etc. Something that is a little discrete can be useful, if you're carrying around a 12 inch bowie knife, you might draw more attention than the knife is worth.
Some inexpensive, high quality knives were looking at are the Mora of Sweden knives They are puukko style shaped knives, but they sell updated versions with plastic handles, hand guards, etc. I like the carbon steel blades, easy to field sharpen, very practical, but if you're around a lot of water they also sell stainless steel and other varieties. The scandi grinds are fantastic for sharpening once you get comfortable with them.
You can find them on Amazon for $10-20 each. They are very useful for skinning, batoning wood, etc. Cheap enough to buy a bunch and light enough to carry it on some cord around your neck. The plastic sheaths are....different. Not a huge fan at this point but they are functional. Some aftermarket custom sheaths are available but they cost far more than the knives! There are also other steel options if you don't like the carbon knives or are concerned about moisture. Some people quite like the triflex steel version, the handle on that version doesn't feel that comfortable for my hands.
The Mora 1 is the classic knife. I prefer the Mora 511, I've bought some for the $10-12 range, and the guard adds a measure of safety. Yes, I hear real men don't need that, the guards are for children, but I like my fingers attached thank you very much. When your hands are cold or you are wearing gloves, it's easy to make a mistake. Much safer for skinning as well.
These knives are commonly referred to as bushcraft knives - they are light, very strong for their size, easy to carry, and great for batoning.
This is the kind of knife recommended by Cody Lundin in his book 98.6 Degrees: The Art of Keeping Your Ass Alive
Another company I quite like is Cold Steel. They sell some bushcraft-like knives, like the Finn Bear. I have yet to try one of these out, they are a stainless steel (4116 Krupp Stainless) and is a puuko-style blade. *edit, I still haven't bought one of these and won't bother now based on reviews I've read/seen. Stick with the mora.
Normally a cheap stainless steel blade isn't something I would use for batoning but they do have a video of it being used to go through a 2x4 - maybe someone can tell me their experience with it?
Cold steel also has an interesting take on the hollow handle survival knife, the Bushman series - very cheap, carbon steel with a hollow handle. You could actually mount them on a pole effectively to make a good spear though i'm not really sure why you would want to in most situations. Very strong knives, good quality. A little on the large side depending on where/when you are carrying it around, very lightweight though.
It's more like a detachable spear than a knife! And probably better used for that too.
Some positives as mentioned are price, strength, and a serviceable sheath for the price. I prefer kydex and I did buy one on ebay but it cost more than the knife. At that price point, it may be best to get a different knife altogether. The hollow handle is all one piece of steel with the blade so it isn't weak like most hollow handle knives. Using a bicycle hand grip or wine corks, among other options, survival items can be stored in the handle. The spear option is cool as well.
When using to baton with, the all-steel handle is not very comfortable, a lot of vibration. Overall this knife is more of a gimmick than a practical knife but with some customization, it's a useful and sturdy tool.
*too many people confuse this with a tactical or fighting knife. More on that in a later post.