I collect/accumulate folding knives, mostly high-end production pieces with a couple semi-custom/custom pieces as well. Usually used for cutting up cardboard boxes/plastic packing/plastic straps and other random stuff, but some perform better than others in terms of blade profile/edge geometry, etc for more specific tasks.

In terms of overall construction, fit and finish, edge retention, and general design in a production (factory made) locking folding knife, Spyderco is at the top of my list at the moment, and Benchmade is a real close second. Camillus, Buck, Kershaw, Al Mar, CRKT, and a few other places make solid knives as well. All of these companies' lineups are fairly affordable, higher end pieces are generally under $150. Microtech makes awesome pieces (think that's a picture of an MT HALO auto someone posted), but they tend to be very high end limited production pieces, starting at $100+.

If you're getting a locking blade, make sure you're buying from a reputable company, because it sucks some serious ass if the blade folds down onto your fingers when the lock fails. Also recommend staying away from linerlocks (leaf spring that comes in from the side to hold the blade in place) if you're planning on heavy use for the knife.

Check out New Graham, Knifeworks, and 1sks.