I own a S.O.G Seal Pup Elite that comes razor sharp out of the box.

When I'm hiking and not hunting, I carry a Cold Steel 'Bushman' as my long knife. Its tapered handle can be mated to my push broom walking stick to make a spear. The Bushman is very tough. Last month I had a discussion with Quinton Schmelzenbach about the Bushman. Its major negative is the lack of a finger guard.
http://www.fieldandstream.com/answers/gear/hunting-gear/what-consensus-c...

While hunting, I wear a Cold Steel 'Boar Hunter'. The Boar Hunter's 8.75-inch blade is great for dispatching wounded deer and pigs. I finished off a 9-point whitetail in January with this knife and then used it for gutting just to see how it would perform. The blade slipped between the ribs with little resistance in quickly killing the deer. But, it was not the best shape or length for gutting.

My wife carries a Buck Model 102 fixed blade when hunting or hiking. I used that knife to gut a small whitetail she shot this season. It’s a great knife.
http://www.amazon.com/BUCK-Woodsman%C2%AE-Model-102-Part/dp/B0001WAOF8/r...

Almost all the time I also carry a locking folder. I like those with thumbholes instead of studs for one-handed opening. My favorite is a discontinued Benchmade but the current production Onslaught looks to be a great knife and is on my wish list.
http://www.amazon.com/Benchmade-741-Onslaught-Plain-Folding/dp/B003D8YGJ...

My lower cost folder that’s similar is the Sogzilla. Lately it’s my favorite large folder for general use. I’ve been told that Benchmade produces these for SOG.
http://www.amazon.com/SOG-Knives-Sogzilla-Stainless-Straight/dp/B0040647...

Sourdough Dave makes a good point in his survival book about making your survival knife into a spear:

"As I have stressed elsewhere, your knife is probably your most critical survival tool. Even if you may be fairly good at it, do not try to take game by throwing your knife. If you break it or lose it you are up the proverbial creek even worse than you were before. Use your knife to sharpen a stick into a spear if need be, but do not make a spear out of your knife by tying it to a stick like you see in the movies. Your knife is just too valuable to risk.” ~ from LIFE IN THE WILD vs. THE ALTERNATIVE

the Rambo knife, fricken bad ass right there.

I'm not real big into survival knives. As outdoor tools, I like my Cold Steel Master Hunter and the Cold Steel Pendelton Lite Hunter. I'm real fond of my Chicago Cutlery 5" boning knives for inside work. I carry a Buck assisted opening folder in my pocket all the time. When it comes to hacking at brush I pull out the Tramontina cane knife.

I carry a sog seal-pup. There are better knives out there if you want to spend an arm and a leg on one, but keeping in a reasonable price range its hard to beat. I have a Ka-Bar that i carry occasionally, also a good knife. Cold Steel and Benchmade both make some nice knives too.

The best knife for survival is a good old fashioned army ka-bar with a sereted blade it can be used for many different things. It can be used to clean deer. Big enough to split timber and just about everything a knife can do.

I have a Randall #27 that I am very happy with. I have a number of Buck, Gerber, and Remington knives that I also like to use.

I have a correction on my previous post. My wife carries the Buck Model 119. It has a 6-inch fixed blade and that is what I used to easily gut a deer in December. Great knife! We bought it at WalMart with a Cordura sheath. Amazon has these with a leather sheath:
http://www.amazon.com/Buck-0119BKS-B-Special-Fixed-Blade/dp/B000EHWWJQ

For survival stay away from serrated, but KA-Bar straight edge is a great knife. Serrations take away your carving area on you blade, if you are stuck out in the bush for a while you will need to be able to carve to a certain degree [ie-traps]. I prefer the Tom Brown Tracker T1 with a Hedgehog Leather Sheath.
http://www.hedgehogleatherworks.com/

There are a lot of great knives out there. I'm a big fan of SOG and Ka-Bar, but generally I look for a knife with a strong thick blade and solid hilt that could be used for hammering if necessary. I'd hate to break my knife in a survival situation.

Lots of responses and good ones, I think the best for survival would be a Leatherman multi-tool but I guess that doesn’t count here. I don't think there is one on the market that meets my specs.

I like a knife with a finger guard on the front. A guard on the back means you can't put your thumb on the back of the blade for carving. There could be a lot of things you need to carve in a survival situation.

A knife with a 6” blade, or longer can be a real life saver if you have to split wet logs to whittle the centre out for dry kindling.

I don't like knives that have a serrated edge at the base of the blade, they are useless for carving. A serrated blade is useful though. I’d like to see a manufacturer put one on the back of a knife at the middle or top.

Thickness of the blade is another thing. I like a blade that is not too thick. Let’s face it, most of the time we are using it for cutting potatoes, cheese, spreading peanut butter, or cleaning fish. The blade needs to be thick enough to be tough though. You may have to throw it on teh end of a spear or split a log. There are always trade offs.

The sheath is important too. A sheath that has no domes or clips to fasten can be another possible life saver. I like being able to access my knife quickly.

Check out the Frontier Fighter at www.silverstag.com They hand make great knives in the u.s.a. using antler handles. You can also get a quick access, holster style sheath with a few of their models.

I too, own a Gerber LMF 2. I thought it was badass, but I broke it in half in less than a month. Its being sent back to gerber this week, we'll see if they warranty it. I tend to disagree about the straight edge debate, I like serrations. Sure they are tough to sharpen in the field, but if you have a good knife, the serrations take forever to dull. Plus, I like the bite for bushcraft...