Snap-On ratchet screwdriver with interchangeable bits is my favorite. Has a bunch of bits in the handle, the bits are even replaced for free if I brake them, but not if I loose them...
I've had a black 6" crescent wrench in my side pocket for 11 or 12 years now (except at the airport), it's very handy, I've about worn two out now, ready for my third, never lost one.
Also keep a General #300 6" pocket scale in (you guessed it) my pocket, handy for all sorts of stuff from prying, scraping, opening doors, removing screws, and even measuring. They wear out every 3 or 4 months, the corners round over and the paint falls out of the markings.
Grigg