I usually carry two pocket knives; an Emerson, and a Spyderco.
Generally I carry an Emerson Commander or CQC-15. Both outstanding knives, and for what you get, I think an excellent value. I've never paid retail, and don't intend to do so.
I also carry a Spyderco Military, or Paramilitary.
There is a big difference, I think, between these knives and many of the less-substantial ones I've owned in the past. I have a number of Emersons and Spydercos. I have Kershaws, Chris Reeve, and others. There's nothing wrong with the Kershaws, but I carry the Emerson for it's features (notably including the "wave," which has proven very handy), and the Spyderco for it's blade and grind.
I've spent a lot of my life working with tools, and learned very early that cheap tools are no bargain. I don't gravitate to the cheapest firearms, nor the cheapest knives.
My Sebenza (Chris Reeve) is an excellent knife, but for the cost, it doesn't get carried so much for the risk of loss or damage. My Emersons have been to some very rough places, and I continue to frequent these places, around the globe. My favorite, a mini-commander, disappeared last year in Iraq, and was quickly replaced by a couple more. In my opinion, they're worth the cost.