If you're looking for a serious "tactical" folder, I would recommend one of the following brands:

Emerson
Zero Tolerance
Spyderco
Kershaw

Pretty much in that order too. None of them are cheap, but if you want a top quality knife, you're going to have to pay for it.

There are other brands that are suitable, but the prices get into the stratosphere pretty quick. A few months ago I had no idea, but you can pay as much for a top name custom knife as you will for a decent handgun.