I carry three tools of choice, 5 if you count the leatherman micra and vic classic I got hanging on the keychain.
First off I carry a buck/strider 880 spearpoint for everyday urban things and work. I work in a warehouse and sometimes the galvanized pipes get clogged with wet packing p-nuts. It helps having a good, beefy folder to punch nice big holes thru it and hack out a 2" x 3" access hole to run fiberglass rods down it to clear the jam. Follow that with a duct tape patch and I'm good to go.
Second, for a handy "toolbox" I carry the victorinox swiss tool for those times when I need pliars or a screwdriver and don't feel like walking halfway thru the plant and unlocking my toolchests.
Lastly, for urban carry and not scaring people half to death by whipping out my large folder, I have a victorinox swisschamp. Handy with tweezers, toothpick and a host of tools (true mostly redundant) that can be used without giving someone a heartattack and scaring the bejesus outta them. Nothing seems to be more innoculous than the red handled swiss army knife for all but the most skittish.

-Bill Liptak