I guess I carry nothing but a folder most of the time. For years a Mercator lockback was the ultimate folder for many of us. I also had a cheap slip joint that travelled with me for many miles. More recently I've been using a cheap Maxam lockback, and it has done quite a bit of work too. I've had a couple of Opinels...I found that they would hold a good edge, and I felt they were more 'socially acceptable' to pull out of my pocket at work or around town. I still like them, but I don't pick them as the most reliable companion to take with me. I broke one blade, and I've had trouble with the wood swelling when wet and making it very difficult to open the blade.
I have a nice Swiss Army 'Rucksack' model. It has a locking blade and a saw. I don't use it much, but it is handy...especially when I'm going for a walk in a reasonably populated area and just might find a nice sapling for a bow or some straight shoots for arrows. And it has a corkscrew... it is the only corkscrew we seem to have in the house, so when my wine-drinking step-daughter visits it can get some use. I feel that this too is a 'socially acceptable' knife that, while it is capable of sticking a pig and gutting it,.... it is less likely to cause raised eyebrows around town.
I've done lots of work with folders.
My dad was an experienced hunter and fisherman and spent a lot of time in the bush. I guess my appreciation for knives came largely from him. He had belt knives, and a few pocket knives. Yet in later years I noticed that he often would not carry one. I'd challenge him about it when we were out together, and he'd say "Why should I bother...you always have one". He just seemed to relax feeling that the universe would provide his needs. And he never seemed to get stuck.
I started by saying I carry nothing but a folder most of the time. That is because I generally always have one with me no matter where I'm going (except on airplanes). But I do carry a fixed blade quite a bit too.... more so nowadays when I hunt and trap. I like them...plus if my hands are cold or wet I feel that a fixed blade is easier to work with. I can also get it in and out of a sheath quickly with one hand... and if the knife or my hand is dirty, I am not continually thrusting a dirty hand and knife into my pocket as I work.
But I like folders. In fact, I'm just waiting for my Cold Steel Voyager medium clip plain blade to arrive in the post. I've had my eye on one of these for maybe a couple of years now. Out of all the folding knives I've ogled over on the 'net, these appeal to me the most. A very pleasing shape, reportedly good quality, can be opened with one hand, and not too danged heavy.
Folders are great....and for real life use I think they are capable of doing the great majority of things that normal people need blades for.