As often as not, I carry a lockback folder, either an Al Marr Sere attack 31/2?, or Gunstock, or a Blackjack folding Mamba. When carried these do the most work over my SAK Hunter.
I would prefer to carry a fixed blade anytime over a folder, but in the UK that is not always "proper". I'm in the process of evaluating a CR Shaddow IV, which I purchased in order that I could have a small enough fixed to slip into a coat pocket. When I post my findings, I think there will be some suprises, as those who follow my posts will already know that I am completely sold on CR Projects.
I've been carrying recently a Leatherman Wave about the house and in the gargen; its been well useful. However, the knife that I cannot leave home, without feeling undressed, is the traditional two blade penknife.