Favorite lock is no lock- small fixed blade, bk14 or the custom I got from hardedge knives. I really dont know why more people here dont carry small fixies- they go into use and go into safe quicker than any folder, are cheaper, stronger, fewer compromises (no thumbstuds or flipper tabs in the way, no spydie holes to make the blade huge wide).
Second favorite is liner lock. Would be frame lock but I am a lefty and always end up with my thumb on the lock bar and making it too hard to open. Third is the low lockback like a buck 110. Hate mid lock backs like cold steels demko lock. No leverage.