I know a lot of people who swear by their Ka-Bars. I would be the first to admit that they are a great fighting knife. I own a Next Generation. I don't have anything bad to say about it except for the finish. I found that the finish on the blade wore off very easily after very little use. So I stripped off what was left with some paint remover and hand polished the blade with some wet-dry sandpaper. But i won't recommend this for a general purpose survival knife. The center of balance is too far back. This makes it a great fighting knife, very quick and agile. But its hell for chopping. For a general purpose backpacking knife I would stongly recommend the D2 Impact Series Combat. Its a bit smaller than the fighting/utility knife, but IMHO very useful in a survival situation.
I also own a RAT-7/D2. It has good geometry and edge holding properties and would make a good survival knife. My only complaint about this knife is the handle. The edges are a bit too square and cause hot spots when doing a lot of chopping. I rounded my handles with a file and finished them with 400 grit sandpaper.
I recently got a Swaprat Ratweiller. I haven't had the opportunity yet to use this in the field, but it should prove to be a great survival knife. Check out the other Swaprat products. You should be suitably impressed.
A couple of other knives you should consider arethe Blackjack Grunt and the Ennis Entrek Companion. Both are a bit smaller, but most survival "experts" recommend a 4"-5" blade for survival sitations. Personally, I prefer something a bit larger, in the 7" range. That's why I went for the Ratweiller. You should also consider the Entrek Buffalo.
Keep in mind that you have to consider what you are going to be doing with your knife and match your knife to the situation. No single knife will do everything well. So you might want to consider carrying one large and one small knive.
-- Blue Orca